Modular lighting system and method employing loosely constrained magnetic structures

ABSTRACT

A lighting system including modules containing LEDs or other electroluminescent devices and loosely constrained magnetic structures at least partially contained within cavities in the module substrate that are connected to fixtures under magnetic force. The loosely constrained magnetic structures accommodate mechanical variations in the system and provide a method to connect modules mechanically, electrically and thermally to different fixtures or positions in fixtures without tools. The relatively short distance separating magnetic structures provides high connection forces with the use of relatively small magnets. Magnets and electrical contacts are not located directly between the LED subassembly and the fixture, which provides higher thermal conductivity pathways to remove heat from the LEDs. Biasing members may be used to increase thermal contact. Magnetic structures may, but are not required, to conduct electricity. Fixtures that attach to modules include rails, sockets, heat sinks and two-dimensional structures with recessed electrodes for improved electrical safety.

This application is a continuation of U.S. non-provisional patentapplication Ser. No. 13/211,533 filed Aug. 17, 2011, which claimspriority of U.S. provisional application No. 61/456,921 filed on Nov.15, 2010; U.S. provisional application No. 61/402,588 filed on Sep. 1,2010, and U.S. provisional application No. 61/514,017 filed on Aug. 1,2011; and is a continuation in part of U.S. non-provisional patentapplication Ser. No. 12/698,731 filed on Feb. 2, 2010 which claimspriority of provisional application No. 61/206,609, filed on Feb. 2,2009 and U.S. provisional application No. 61/279,391 filed on Oct. 20,2009; all of which are included herein in their entirety by reference.

COPYRIGHT NOTICE

A portion of the disclosure of this patent contains material that issubject to copyright protection. The copyright owner has no objection tothe reproduction by anyone of the patent document or the patentdisclosure as it appears in the Patent and Trademark Office patent filesor records, but otherwise reserves all copyright rights whatsoever.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to modular lighting. In particular, itrelates to magnetically restrained lighting systems and methods of use.

Description of Related Art

Modular track lighting systems have been available for decades and wereoriginally designed to use incandescent light bulbs. These systemstypically have included fixtures that are mounted to rigid tracks withspring contact tabs that are rotated into contact with linearconductors, thereby providing electrical power to the lighting module.For electrical mains voltage safety, these linear conductors areshielded from direct finger contact. More recently, suspended rail andwire systems have been introduced that include insulation piercingcontacts and/or use inherently safe lower voltages. These systemsgenerally require tools for mounting individual lighting fixtures.

In recent years, there has been interest in solid-state lightingsystems, in particular, light emitting diodes (“LEDs”). These systemstend to be smaller in size, longer-lived, and more efficient thanstandard incandescent light bulbs. Magnetic attachment of LED lightingmodules has been proposed, for example, in U.S. Pat. Nos. 7,726,974 and7,806,569 to eliminate the need for a tool to attach the LED lightingmodules along the length of the track.

Although visible LEDs are efficient in that they do not generatewasteful infrared radiation and they generate less heat thanincandescent systems, they do create some waste heat that must beremoved from the emitting junction by thermal conduction to avoiddegradation in performance or reliability since they are more sensitiveto heat than incandescent systems. Existing magnetic attachment systemshave limited thermal cooling efficiencies which restrict their powercapability for general illumination applications with high-brightnessLED assemblies since the greater the number of LEDs, the greater theheat generation and the greater the degradation problem. The proposedsystems in U.S. Pat. Nos. 7,726,974 and 7,806,569 rely upon cooling bythermal conduction directly through the magnetic material and convectioncooling through passive air movement near the LED subassembly. Neodymiumand ferrite magnets have thermal conductivities that are approximately10, 20, and 40 times less than that of iron, aluminum, and copper,respectively. The thermal conductivity of air is three orders ofmagnitude less than iron. Excess thermal interfaces in the conductionpath between the LED subassembly and the external heat sink generallyadd to cooling inefficiencies.

Existing magnetically attached systems often include interface elementsthat require precision mechanical tolerances for proper attachment.Planar magnets and rigid contacts “rock” on non-planar surfaces reducingcontact areas for thermal conduction or the ability to accommodatemechanical variation. Also, the number of electrical contacts that canbe attached uniformly is limited. Thermal expansion effects furtherincrease the level of precision required in these interfacing parts.Note also that lighting modules that are exposed to heat often changetolerances due to frequent heating and cooling cycles.

In addition to track lighting systems, the higher performance of solidstate lighting has generated interest in replacement systems suitablefor existing incandescent screw sockets. Available one-piece standardscrew-in incandescent bulb replacements using solid state lightingcombine less reliable electrolytic capacitors with higher reliabilityand more expensive LED subassemblies in a single field replaceable unit.Differences in functionality such as dimming in the integratedelectronics result in stocking completely different units or includingunused functionality and unnecessary parts cost. Although two piecedesigns have been proposed, these proposals have not provided details onhow a mechanical, electrical, and thermally efficient mounting of theLED subassembly can be accomplished to the socket with highermodularity.

Even in current solid state lighting systems that are not meant to fitin an existing incandescent lighting fixture, differences in functionalattributes including power output, emitted light spectral, ordirectional characteristics create increased costs to businesses andconsumers. A need exists for a highly-modular, robust system forcreating reliable interconnecting between lighting system elements.

Rapidly rising prices for rare earth elements has increased the cost ofrelatively strong magnets and as such, while useful, they are becomingimpractical for lower cost lighting systems. Existing lighting systemsfail to simultaneously optimize the mechanical, electrical, and thermalperformance especially with smaller, less expensive magnets whichrequire the stronger magnets to properly make and retain a connection.

Insulation piercing contacts have been proposed for electrical safetyand environmental considerations, but the mechanical forces required topierce insulators may be higher than the magnetic force available evenwith use of rare earth magnets. Insulation piercing contacts permanentlychange the system which may introduce aesthetic or safety issues when amodule is removed or moved within the system. There is a need foralternate approaches for electrical safety that provide greaterflexibility in attachment without damage or requiring a onetimeattachment.

Lighting modules can be difficult to seal from the environment whilemaintaining electrical/mechanical and thermal performance and this addsto the difficulties with magnetic attachment of an electrical connectionfor a lighting system.

While some systems attempt to address one or more of these problems, aneed still exists for a solid state lighting system solution thatprovides a robust mechanical, electrical and/or thermal interfaceattachment mechanism using magnetic materials that is modular andincludes a wide range of fixture mounting options.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to the discovery and invention wherein amagnetic connection also includes the electrical connection between alighting module and a lighting fixture without requiring mechanicalprecision where parts interface. In further embodiments, the inclusionof a heat sink for removing heat further improves the present invention.

Accordingly in one embodiment there is a lighting system comprising:

-   -   a) a lighting module comprising one or more electrically powered        LEDs;    -   b) a thermal conduction pathway for removing heat from the one        or more LEDs;    -   c) a lighting fixture for attaching a lighting module comprising        electricity for powering the one or more LEDs;    -   d) a magnetic connection between the lighting module and the        lighting fixture for attaching comprising at least one loosely        constrained magnet or material to which a magnet is attracted        wherein the thermal conduction pathway does not essentially pass        through the magnet; and    -   e) wherein the electricity is delivered to the one or more LEDs        where the lighting module is connected to the lighting fixture        via the magnetic connection.

Another embodiment is a lighting system comprising:

-   -   a. a lighting module comprising one or more electrically powered        LEDs;    -   b. a thermal conduction pathway;    -   c. a lighting fixture for attaching a lighting module comprising        electricity for powering the one or more LEDs;    -   d. a magnetic connection wherein components of the magnetic        connection are fixed in position; and    -   e. wherein the one or more LEDs are mechanically biased to be        held against the thermal conduction pathway when the light        module is magnetically attached to the light fixture.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top isometric view of a magnetic lighting module (“MLM”).

FIG. 2 is a bottom isometric view of a MLM bottom.

FIG. 3 is a top exploded isometric view of a MLM.

FIG. 4 is a bottom exploded isometric view of a MLM.

FIG. 5 is an isometric view of a flat track electrode with an MLM.

FIG. 6 is a section view of FIG. 5 of flat track electrode with MLM.

FIG. 7 is an isometric view of a triangular rod track electrode withMLM.

FIG. 8 is a bottom view of a module with elongated contacts.

FIG. 9 is a section view of FIG. 8 (module and rod track).

FIG. 10 is a module with permanent magnets attached to circuitry.

FIG. 11 is a module with auxiliary outer housing with contacts.

FIG. 12 is a top isometric view of a lighting module assembly withintegral heat sink.

FIG. 13 is a bottom isometric view of a lighting module assembly.

FIG. 14 is a top exploded isometric view of a lighting module assembly.

FIG. 15 is a bottom exploded isometric view of an integral heat sinkwith flexible assembly.

FIG. 16 is a top isometric view of an integral heat sink with flexibleassembly.

FIG. 17 is a bottom isometric view of an integral heat sink withflexible assembly.

FIG. 18 is an exploded isometric view of a substrate level MLM.

FIG. 19 is a section view of substrate level MLM on heat sink withrails.

FIG. 20 is a view of concentric substrate MLM contact pads on heat sink.

FIG. 21 is an example of an FPC laminated to ferromagnetic electrode.

FIG. 22 is a top isometric exploded view of a lighting module and socketwith wrapped flexible magnetic contacts.

FIG. 23 is a bottom isometric exploded view of a lighting module andsocket with wrapped flexible magnetic contacts.

FIG. 24 is an isometric view of a lighting module with magnetic andmechanical spring contacts.

FIG. 25 is an example of a facetted heat sink with multiple lightingmodules and sockets attached.

FIG. 26 is an isometric view of rotary magnetic lighting modulesinstalled on cylindrical electrode tracks.

FIG. 27 is a top view of a rotary lighting module of FIG. 26.

FIG. 28 is a side view of a rotary lighting module of FIG. 26.

FIG. 29 is a vertical position of a section view of rotary lightingmodule.

FIG. 30 is a rotated position of a section view of a rotary lightingmodule.

FIG. 31 is a section view of a vertical rotation of a rotary magneticlighting module with can fixture.

FIG. 32 is a section view of a rotary magnetic lighting module with canfixture in a rotated position.

FIG. 33 is a section view of a rotary magnetic lighting module withmovable captured magnetic actuators and can-type fixture.

FIG. 34 is a section view of a rotary magnetic lighting module withmovable captured magnetic actuators in a rotated position and can-typefixture.

FIG. 35 is a top exploded view of compliant thermal MLM.

FIG. 36 is a bottom exploded view of compliant thermal MLM.

FIG. 37 is a top isometric view of a compliant thermal MLM assembly.

FIG. 38 is a bottom isometric view of a compliant thermal MLM.

FIG. 39 is a module with housing and stamped sheet metal circuitry.

FIG. 40 is an exploded view of thermal MLM, low profile socket and heatsink.

FIG. 41 is a top view of thermal MLM, socket and heat sink.

FIG. 42 is a section view of FIG. 41 of thermal MLM prior toinstallation into socket.

FIG. 43 is a section view of FIG. 41 module assembled into socket.

FIG. 44 is a detail view of contact area of MLM and base of FIG. 41.

FIG. 45 is a multiple LED array module prior to installation in socket.

FIG. 46 is a multiple LED array module installed in socket.

FIG. 47 is a module incorporated into conventional incandescent screw-infixture.

FIG. 48 is an isometric view of an electrode grid.

FIG. 49 is an exploded isometric view of an electrode grid.

FIG. 50 is an isometric view of a selectively shaped ferromagnetic gridlayer structure.

FIG. 51 is an exploded isometric view of a selectively shapedferromagnetic grid layer structure.

FIG. 52 is a bottom isometric view of a grid lighting module.

FIG. 53 is a section view of a grid lighting module and heat sink moduleattached to a grid.

FIG. 54 is a bottom view of a grid lighting module.

FIG. 55 is a top view of grid lighting modules mounted to a grid.

FIG. 56 is an exploded isometric view of grid lighting modules, heatsink modules and a grid.

FIG. 57 is an isometric view of grid lighting modules and heat sinkmodules mounted to a folded grid.

FIG. 58 is a section view of a grid lighting module and heat sink modulewith an electrode grid with openings.

FIG. 59 is a section view of a lighting module and heat sink moduleattached to track electrodes.

FIG. 60 is a section view of an alternate lighting module and heat sinkmodule attached to track electrodes.

DETAILED DESCRIPTION OF THE INVENTION

While this invention is susceptible to embodiment in many differentforms, there is shown in the drawings and will herein be described indetail specific embodiments, with the understanding that the presentdisclosure of such embodiments is to be considered as an example of theprinciples and not intended to limit the invention to the specificembodiments shown and described. In the description below, likereference numerals are used to describe the same, similar orcorresponding parts in the several views of the drawings. This detaileddescription defines the meaning of the terms used herein andspecifically describes embodiments in order for those skilled in the artto practice the invention.

The terms “a” or “an”, as used herein, are defined as one or as morethan one. The term “plurality”, as used herein, is defined as two or asmore than two. The term “another”, as used herein, is defined as atleast a second or more. The terms “including” and/or “having”, as usedherein, are defined as comprising (i.e., open language). The term“coupled”, as used herein, is defined as connected, although notnecessarily directly, and not necessarily mechanically.

The terms “about” and “essentially” mean±10 percent.

Reference throughout this document to “one embodiment”, “certainembodiments”, and “an embodiment” or similar terms means that aparticular feature, structure, or characteristic described in connectionwith the embodiment is included in at least one embodiment of thepresent invention. Thus, the appearances of such phrases or in variousplaces throughout this specification are not necessarily all referringto the same embodiment. Furthermore, the particular features,structures, or characteristics may be combined in any suitable manner inone or more embodiments without limitation.

The term “or” as used herein is to be interpreted as an inclusive ormeaning any one or any combination. Therefore, “A, B or C” means any ofthe following: “A; B; C; A and B; A and C; B and C; A, B and C”. Anexception to this definition will occur only when a combination ofelements, functions, steps or acts are in some way inherently mutuallyexclusive.

The drawings featured in the figures are for the purpose of illustratingcertain convenient embodiments of the present invention, and are not tobe considered as limitation thereto. Term “means” preceding a presentparticiple of an operation indicates a desired function for which thereis one or more embodiments, i.e., one or more methods, devices, orapparatuses for achieving the desired function and that one skilled inthe art could select from these or their equivalent in view of thedisclosure herein and use of the term “means” is not intended to belimiting.

As used herein a “lighting system” refers to a system of devices,modules, fixtures, etc., which when combined, provide lighting in aparticular environment. In this particular invention it refers to an LEDlighting system and in general a two part system as described below andshown in the figures and claims.

As used herein for the purposes of this disclosure, the term “module”should be understood to mean any individual element of the system thatmay be connected to a separate device (a fixture or another module)using a magnetic connection force.

As used herein a “light module” or “lighting module” should beunderstood to be a module that includes an element that radiateselectromagnetic energy, e.g. light. The element may be one or morepackaged or unpackaged light emitting diode, or LED, with an inorganicor organic active element, a lamp, an electroluminescent material, orany other material or component with an electro-optic energy conversion.Examples include lamps for track lighting, chandeliers and sockets orextended lighting arrays in buildings or other temporary or permanentstructures, vehicles, or vessels. As used herein, “one or more LEDs”refers to a single or multiple LED and includes an “LED subassembly” or“LED light engine” and should be understood to generally comprise one ormore semiconductor die or other solid state light emitting structureswhich are packaged on a shared electronic substrate. It indicates thatthe LED is electrically powered by appropriate electrical current eitherdirectly or by use of a transformer converting one type of electricalpower (AC) to another type, voltage or amperage.

Although the terms one or more LED and LED subassembly are used inillustrating the inventive concepts contained in this disclosure, thisis for descriptive convenience and does not preclude the substitution ofother types of lighting technologies for the LEDs where magneticattachment and heat dissipation are at issue for improved performance.The spectrum of electromagnetic energy associated with a light module isnot restricted to the visible region, but may consist of electromagneticenergy with frequencies outside the visible region. The lighting modulesdescribed herein may also contain passive and active electricalcomponents to facilitate features such as current or voltage control,data communication to or from the module, and functional attributes suchas intensity, spectral changes, pulsing, etc.

A lighting system includes at least one “lighting module” connected to aseparate “lighting fixture” via a magnetic connection. A “magneticconnection” for the lighting system includes at least one connectionbetween the lighting module and the lighting fixture for attaching thelighting module to the lighting fixture wherein the electricity from thelighting fixture is delivered to the lighting module to power the one ormore LEDs as a result of the magnetic connection.

As used herein the “lighting fixture” is a device which provideselectrical power to a lighting module when the lighting module isconnected to the lighting fixture. Examples of “lighting fixtures”include electrical power source or data connections such as sockets,connectors, tracks, rods, rails, wires or grids; heat sinkingassemblies; modules that are used to extend the electrical and/ormechanical extent of any system; or another light module that ispowered.

A module “substrate” should be understood to be at least a part of thestructure that mechanically supports an individual light emittingcomponent, multiple LEDs, or an LED subassembly in the lighting module.Although planar substrates are illustrated in this disclosure, theinventive concepts should be understood to be applicable to othergeometries. In general, substrates in this disclosure can be anepoxy-glass (e.g., FR4) printed circuit board (“PCB”) material, ceramicsubstrate, metal-core PCB, rigid-flex PCB, molded circuit substrate,flexible circuitry, combinations of these, or other electronic substratematerials or assemblies known in the electronic packaging arts.

As used herein, a “thermal conduction pathway”, or a “heat sink” shouldbe understood to be an element that is incorporated into a lightingsystem to remove or redistribute heat from a light module, LED or otherheat source through thermal conduction with these heat sources. Apassive heat sink commonly comprises a metal structure of greaterphysical volume than the heat source element in physical contact withthe heat source directly or through additional material layers to createa thermal conduction pathway. These elements may in turn transfer heatto other elements or the surrounding environment, for example, byconduction, convection, or radiation processes. External heat sinks areheat sinks that are designed to be separable from a module or fixture.The heat sinks may include channels, fins or other geometries toincrease surface area, fluid-filled heat pipes and/or active coolingtechnologies including fans, thermoelectric coolers, or other heattransfer and management technologies. Heat sinks in some embodiments ofthis disclosure may also participate in supplying electrical powerdirectly by electrical conduction or by mechanically supportingelectrical conducting elements. It should be understood that the LEDs orother light sources, may be mounted on an intermediate heat-conductingcomponent, including either a passive heat spreader/conductor, or asubstrate containing circuitry and other components. These substratesonto which light sources are mounted may contain other thermal featuressuch as thermal vias and integrated thermal conductive components thatare subsequently coupled to the modular heat sinks and grids describedherein.

Thermal conductivity of a material is dependent upon materialcomposition and environmental conditions. The removal of waste heat bythermal conduction is also dependent upon the geometries of systemelements. In this disclosure, whether a material would improve coolingof heat sources is relative to other materials in the system. In ageneral sense, materials that are typically considered to haverelatively high thermal conductivity include metals, metal alloys andsome metal oxides, semiconductors, some ceramics, diamond and otherforms of carbon. Specialty materials called “thermal grease”, “thermaladhesives”, “thermal pads” or other filled or composite materials orstructures may be incorporated into modules or fixtures to bridgeinterfaces to improve thermal conduction, especially if air would beincluded in the thermal conduction path otherwise. Although some ofthese specialty materials have characteristic material thermalconductivities on the order of magnetic materials, they have the thermalefficiency advantage over magnetic materials of being of practical usein thinner layers that conform to local mechanical variations betweenrigid parts. Thermal conduction pathways may comprise these specialtymaterials.

If not otherwise noted, “top” or “front” refers to the principalemitting side of the light module, and “bottom” or “back” refers to theside of the module which attached to the light fixture and in someembodiments is attached to the heat sink. These directions are forconvenience in referring to the illustrated embodiments and are notmeant to be attached to the top or bottom of a module with the inventiveconcepts disclosed. Similarly, the terms “hole”, “cored space”, or“cavity”, when referring to a structure should be interpreted to referto an open space or void that extends at least partially through thethickness of the structure. The term “through hole” or “window” shouldbe interpreted as an opening or aperture that forms a passage thatextends from one side of a structure to another side of the structure.

As is well known, magnetic forces may exist between pairs of magnets andbetween a magnet and a material attracted to a magnet. Magnets andmaterials attracted to magnets comprise rare earth and ferromagneticmaterials. Rare earth magnets comprise neodymium and samarium-cobaltalloys for example. Ferromagnetic materials comprise iron, nickel,cobalt, gadolinium and alloys comprised of these materials such asalnico. The properties of the poles or magnets are also well-known, asis the ability to form magnets from cast and sintered material ormagnetic particle filled elastomers and polymers. As a result, as usedherein for the purposes of this disclosure, the term “magneticconnection’, “magnetic structure” or “magnetic material” should beunderstood to include either a magnet or a material attracted to amagnet for the purpose of attaching the lighting module to the lightingfixture.

As used herein the phrase “magnetic connection” for the purposes of thisdisclosure includes the combination of at least one magnet and at leastone ferromagnetic material (which also could be a magnet) for thepurpose of making a magnetic connection. The ferromagnetic material insuch a combination may be used to influence the distribution of themagnetic flux lines of the magnet. The ferromagnetic material in such acombination may also be used to shape contact geometries. Although notspecifically shown in the figures, it is understood that in addition to“permanent magnets,” “temporary magnets” may be created by magneticinduction to create magnetic forces that could be used with the lightingmodules and systems illustrated. Unless there is specific mention toorientation of magnetic poles, it should be understood that at least oneor the other of the two magnetic structures creating an electricalcontact pair from a magnetic attraction is a magnet. Due to theinterchangeability of which element in the pair is a magnet, it shouldbe understood for the purposes of this disclosure that a description ofa contact pair in which one magnetic structure is described as a magnetand the other as a magnetic material also discloses an equivalentstructure in which the materials of the magnetic structures of bothhalves are switched. In addition, a magnetic material in embodimentsdiscussed herein may be replaced with a magnet if one of the magnets ina contact pair is free to reorient magnetic poles to create anattractive force, or is by other means mechanically oriented such thatthere is magnetic attraction between the adjacent magnetic poles.

As used herein a “loosely constrained” magnet or a “moving magnet” forthe purposes of this disclosure is to be understood to be a magnet ormagnetic structure that has some limited range of motion under magneticforces between a module and fixture as a result of its size and shaperelative to physical constraints provided by the portions of a module inwhich it is located. The loosely constrained magnet of a fixture ismovably connected to the unmovable portion of the fixture, that is, therelative position of these two bodies can change over a limited range.The loosely constrained magnet is preferably retained in the modulemechanically, but may be retained by magnetic force in the absence ofmechanical retention features. To be loosely constrained for the case ofa magnet attached with adhesive to an electronic substrate, such as aflex circuit or metal foil, the substrate must be sufficiently flexibleto readily locally deform as a result of the magnets attractive force tothe other non-magnetic element through a distance longer than mechanicaltolerances of a particular interface and design. For example, spherical,neodymium magnets of 3 mm diameter are capable of deforming 0.1 mmcopper foil by several times the foil's thickness perpendicular to thefoil and would be sufficiently loose in this direction to have apractical motion range for interface mechanical tolerances.

Magnetic attachment forces may be supplemented with other mechanicalattachment elements, particularly when lighting system applicationenvironments are extreme or there is less need for repositioning ofelements. Magnetic structures may be coated or filled with material thatincreases electrical conductivity compared to the characteristicelectrical conductivity of magnets which is not practical for mostelectronics purposes.

Magnetic structures and/or electrical contacts used in embodimentsdisclosed herein may be shaped to influence mating contact geometriesand associated Hertz stress of an electrical contact pair. The shape ofthe magnetic structure may contribute at least temporarily to theHertzian contact stress profile through deformation of a compliantcontact. Other structures including asperities, permanent deformations,and additional conducting material attached to the contact surface maybe incorporated into one or more contact surfaces to contribute to theHertzian contact stress profile as is well-known in the art ofelectrical interconnects. In one embodiment the magnets are globular inshape and in other embodiments they are cylindrical, which are readilyavailable magnetic shapes. There is no requirement that a particularshape is utilized and one skilled in the art can utilize essentially anymagnet shape as desired.

As used herein the term “low voltage” when used in an electrical safetyperspective in this disclosure should be understood to be an AC or DCvoltage that is lower than the voltage at which the risk of injury tohumans from electrical shock is considered to be acceptably small, whichis generally determined by some electrical safety standards to be in therange of tens of volts or less.

The term “spring” or “spring member” for the purposes of this discussionis a structure that is made of resilient material. Highly resilientmaterials include spring steel, stainless steel, phosphor bronze, andother metals as well as elastic foams, various forms of elastomericacting polymers, and rubbers. For the purposes of this disclosure,springs of different materials may be used to provide a compressivemechanical bias force at the interface between two bodies. Structuresincluding some substrates and electrical contact assemblies may alsohave some inherent resiliency that may provide some spring-likemechanical bias or loading.

This disclosure describes methods and designs for producing modularlighting systems suitable for LED or other emissive technologies. LEDlighting modules disclosed employ magnetic attachments to provideelectrical interconnection for power and control, and mechanicalretention and/or a thermal conduction path to a heat sink. In someembodiments, the system comprises a ferromagnetic track or grid systemthat may be easily assembled with a variety of alternate heat sinksdesigned for a specific lighting application's thermal, environmental,mechanical, and industrial-design constraints. In some embodiments, theelectrical track or grid system contains a ferromagnetic or magneticattachment component and a thermal interface conduction path to a heatsink onto which a lighting module may be attached at multiple positions.Lighting modules containing permanent magnets are magnetically attachedto the track/grid system, simultaneously providing electrical,mechanical, and thermal attachment. Also disclosed are socket stylemagnetic lighting modules, other examples of modules containing integralheat-sinks and lighting modules with pivoting magnetic connections.

According to one aspect of the disclosure, a lighting module comprisesone or more loosely constrained magnets positioned in a cavity orthrough a hole of a substrate that is associated with an LED lightingsub-assembly or the lighting module. These moving magnets are attractedto magnetic material in a mounting fixture and create mechanical andelectrical connections to the fixture. In some embodiments, the movementof the magnets provides greater capability in accommodating mechanicalvariation of either side of the interface, for example, wheremanufacturing tolerances vary enough to require some flexibility inmounting specifications. This tolerance of mechanical variation may beaccomplished by allowing the magnets to move in one, two, or threedimensions. In some embodiments, the magnets have sufficient clearancespace in a cavity to self-orient to provide higher magnetic force. Ofcourse, the location of a moving magnet may be in the fixtures insteadof in the module or may be in both the module and the fixture withoutdeviating from the inventive concepts of this disclosure.

According to some embodiments of this disclosure, the electrical contactlocations are directly between the magnets of the module and themagnetic material of the fixture. Since the magnets are not located inthe principal thermal conduction pathway between the LED subassembly ofthe module and the heat sinking interface of the fixture, the thermalconduction properties of the magnets do not substantially impact LEDsubassembly cooling. According to some embodiments of the disclosure,the moving magnets do not directly conduct electricity between the LEDsubassembly and electrical contacts in the fixture. In these cases, itis not necessary to provide an electrically conducting coating to themagnets or to use magnets that are sufficiently electrically conductinginherently to function as part of an electrical circuit.

According to some embodiments of the disclosure, magnets are looselyconstrained in part by a metal foil, milled PCB or flexible circuitwhich forms the electrical contact or contact pad where a separableelectrical interconnection is established. Various methods are proposedfor forming this contact. In some embodiments, the magnet may beattached to a member that is capable of moving and/or deforming as aresult of the magnets attractive force to another magnetic connectionelement through a distance larger than mechanical tolerances of aparticular interface.

According to some embodiments of the disclosure, the cavity or throughhole in the substrate containing the magnet provides a separationdistance between the magnet and the magnetic material across theseparable interface of less than or equal to 0.3 mm to provide a strongmagnetic force of attraction even with relatively small magnets comparedto the overall size of the module.

According to some embodiments of the disclosure, a flexible circuit isused to provide a wiring connection to the LED subassembly and form theelectrical contact by using a metal substrate as a heat spreader for theLED subassembly.

According to some embodiments of the disclosure, the substrate has anopening directly underlying the LED subassembly to reduce the number ofthermal interfaces between the LED subassembly of the module and theheat sinking fixture to which it is attached. According to someembodiments, a compressible thermal conduction pad or other thermalconducting material is positioned adjacent to the bottom of the LEDsubassembly. According to some embodiments, a spring or elasticstructure is used to provide a biasing force on the thermal interface ofthe LED subassembly. According to some embodiments, the loosely retainedmagnets compress a thermal conduction material adjacent to the LEDsubassembly when the mechanical and electrical attachments are made. Insome embodiments, the magnets are located symmetrically outboard of anLED subassembly to apply uniform pressure to the thermal interface.

According to some embodiments of this disclosure, the magnetic lightingmodules are connected to fixtures having parallel linear electrodes inthe form of ferromagnetic strips, rods or wires, sockets withferromagnetic contacts, or planar or three-dimensional ferromagneticelectrodes. According to other embodiments of this disclosure, theelectrodes are not directly made of magnetic material, but are attachedto heat sinks or other structures that are made of or include magneticmaterial.

According to some embodiments of this disclosure, the magnetic lightingmodules and lighting fixtures allow pivoting, rotational and/ortranslational relative movement while maintaining electrical,mechanical, and thermal connection.

According to some embodiments of this disclosure, the magnetic lightingmodules have a protruding magnetic contact which connects to an innerelectrode, in a grid electrode assembly on the lighting fixture.

According to some embodiments of this disclosure, auxiliary magnetswhich do not participate in electrical conduction are used to attachauxiliary heat sinks to a module directly or to a fixture beside orunder a module or to increase the magnetic force of attraction on amodule for increased retention or thermal management. Additional magnetscan be utilized to attach the lighting fixture and module which do notparticipate in the electrical connection and or thermal connection.

Now referring to the figures, the inventive concept is illustratedthrough reference to the figures in this disclosure and conceptsdisclosed in the referenced applications. FIG. 1 and FIG. 2 are top andbottom isometric views of an exemplary embodiment of a magnetic lightingmodule (“MLM”) 1. FIG. 3 and FIG. 4 are exploded views of FIG. 1 andFIG. 2.

The exemplary magnetic lighting module of FIG. 1-FIG. 4 comprises modulesubstrate 2 with integral contacts 3, to which a variety of electroniccomponents may be attached such as LED subassemblies 4, and passive andactive electronic components, as required for the function of thelighting module. These components may be attached using standard PCBpick-and-place and soldering processes or other electronic manufacturingprocesses known in the art, thereby providing an inexpensive modulemanufacturing process. Permanent magnets 5 are located adjacent to andin contact with the integral contacts 3. Spherical permanent magnets 5are shown in this example, but other regular shapes such as cylindersand discs may be used, or non-regular geometric shapes may be employed.

Permanent magnets 5 may be attached to integral contacts 3, such as withadhesives, or as shown in FIG. 3 and FIG. 5, may be non-rigidly locatedadjacent to the center of integral contacts 3 within cored structures 6.In this example, mechanical retaining features 7 incorporated into anexemplary lens 8 provide mechanical structures complimentary to thecored structures to loosely constrain magnets 5.

Completing the exemplary lighting module of FIG. 1-FIG. 4 is a spacer 9and lens 8, which function to create a cavity containing all of theelectronic components. Attaching the spacer and lens to each other andthe substrate may be used to seal the electronic components from theexternal environment. The integral contacts 3 and the substrate 2provide a seal on the opposite side of the module. Any open vias may befilled or covered with a solder mask or other material to seal thesubstrate in the area of the substrate defined by spacer 9. Spacer 9 maybe constructed of materials or shaped to provide additionalfunctionality besides sealing. For example, spacer 9 may optionallyfunction as a heat sink by including features such as aluminum or copperfins or other structures. In another embodiment, the spacer and lens maybe formed as an integral unit by a molding process using transparentmaterial. The lens may incorporate features to modify the distribution,direction or spectral content of light emitted from the LEDs.

In this illustrative example module 1, it should be evident that all ofthe electrical components can be completely sealed from the environmentto prevent contamination ingress to the electronic components in thecenter of the module. However, the outer flange, i.e., the area outsideof the spacer, of the substrate 2 may function as a heat sink and/orheat spreader and may include vias and other openings extending throughthe substrate 1. These openings may increase the surface area availableor otherwise increase convection cooling or provide a thermal conductionconduit from the electronic components sealed within the cavitydescribed above.

Module substrate 2 would typically be an epoxy glass printed circuitboard, ceramic substrate, metal-core PCB, rigid-flex PCB, molded circuitsubstrate, or another electronic substrate material known in theelectronic packaging arts. The module substrate would typically comprisea copper-clad laminate with layers of copper 10 or other electricallyconductive metal or other material with which to fabricate desiredcircuitry 11 by PCB and substrate manufacturing technologies known inthe art of electronic manufacturing.

In an exemplary embodiment, module substrate 2 is composed of core 12 ofa standard epoxy-glass PCB (approximately 0.04-0.125″ thick) with copperfoil 10 (˜0.001-0.005 inch thick) laminate on one or more layers, as iscommon in PCB manufacture. In one method of forming integral contacts 3,the core material of the PCB is removed from the top side by routing,drilling and/or laser ablation down to the copper foil material on thebottom side, which is the module contact side, of the board, leaving thecopper foil suspended adjacent to the cored structures 6. The coredstructures may be routed or milled to a distance within approximately0.005″ of the copper foil, and subsequently any remaining core materialremoved by laser ablation, leaving the exposed copper foil. Note that itis not required that all insulating material be removed in order for thesubject contact to function. Thus, a suspended integral contact isformed as a part of the PCB manufacturing process, and is integrallyattached to the in-situ circuitry 11 on the PCB. The integral contactsmay be formed at any point during the PCB manufacturing process, forexample, using conventional routers, or may be formed as a secondaryfinishing process after the PCB is complete. Other features may beincorporated into the dielectric material and conductor pattern totailor the mechanical properties of the contact system. For example,slits, and routed patterns to preferentially make locally separated orthinned regions of the substrate may be added to tailor compliancy ofthe contacts. Copper patterns may also be etched to control compliancy;for example slits or traces radiating out from a center conductor padprovide modified compliancy of the contact. Additionally, othermaterials may be added within the cored area to modify the contactproperties, such metallic or organic coatings and films.

Secondary operations in the manufacturing process can also be used tocreate cavities for magnets and contact pads by attaching discretecontact pads that span through-holes in the substrate. The separatecontact structures may be comprised of conductive metal foils,optionally formed before or after attachment, or structures formed intoflexible printed circuit or other PCB materials. The separate contactstructures are attached to the circuitry 11 of the substrate 2 bysoldering, conductive adhesives, welding, or other means known in theart of electronic packaging.

Depending upon the thickness of the metal foil, shape of the cavity, andcharacteristics of the permanent magnet that will be placed in thecavity, the resulting integral contact may be relatively rigid or stiff.An overly stiff planar contact that is flush with the bottom of themodule substrate may inhibit good contact to an external power sourcehaving planar contacts. It is desirable to have the integral contactproject below the plane of the substrate 2. (The above referencedprovisional and non-provisional patent applications describe flexiblemagnetic contact designs comprising contacts that are sufficientlycompliant to create reliable electrical contacts with this geometry.)The metal conductor surfaces and contacts of the substrate may be platedwith a variety of corrosion resistant materials such as nickel-gold,nickel-tin, etc.

Also, a non-planar contact is desirable for consistent electricalcontact force and Hertzian stress considerations. Consequently anembossing or coining procedure may be used to produce a relativelynon-compliant formed contact point that projects below the surface ofthe substrate. While relatively stiff contacts, i.e., contacts that donot change shape under the action of the magnet, may accommodatemechanical tolerances for the modules with two-contacts shown in FIG. 2,flexible contacts as described in the referenced patent applications arepreferred when the module has more than 3 contacts. For example, anembossed spherical surface 6 in an integral contact of 0.250 diameter iseasily produced in copper foils of 0.0014 inch thick, that project ˜0.03inches below the module substrate surface. Other parts may be bonded tothe interior or exterior surfaces of the contact to provide similarlyshaped contact points, but the aforementioned coining method isinexpensive. Another advantage of coring the substrate is that itminimizes the distance from the magnet to the ferromagnetic externalcircuit connection as described below.

Allowing the magnets 5 to freely move within the retaining feature,negates any need for orienting magnets during module assembly that havesufficient clearance to reorient in the cavity after assembly, avoidsadditional stresses on the metal foils of the integral contacts, andallows self-orienting of the magnets during use in the maximum magneticflux and force direction. Spherical magnets, or other curved shapedsurfaces of the magnets, or additional pieces attached to the magnets(such as ferromagnetic parts with spherical surfaces), provide goodHertz contact stress and minimal mechanical stress on the integralcontact foils.

Such features as the lens, spacer ring, etc. described above are notrequired for the basic function of the integrated magneticinterconnects. The only basic components required are the substrate withintegrated contact and magnet. For example, LED components may be adirect chip attached to the substrate with thermal vias for low thermalresistance, and protected with a dispensed encapsulant, with magnetseither adhered to the integrated contact pads or mechanically retainedwith a separate part or feature.

In operation, the module with integrated contacts is attached to a powersource and/or other electronic interface circuitry; this sourceinterface circuit includes ferromagnetic components to produce magneticelectrical contact force and mechanical retention. Referring to FIG. 5and FIG. 6, in an example embodiment, lighting modules 1 aremagnetically attached to a flat track 13 containing ferromagneticelectrode strips 14 (positive) and 15 (negative), separated by aninsulator 16 connected to a low-voltage DC or AC power source 17. Themagnets 5 are attracted to the ferromagnetic electrode strips 14 and 15,compressing the integral contacts 3 and establishing electricalinterconnection and mechanical retention. FIG. 6 is a sidecross-sectional view through module 1 and track 13. The module isreadily repositioned at different positions on the track without a tool.Alternate flat track designs compatible with the magnetic lightingmodule may be comprised of non-ferromagnetic conducting strips such ascopper foil attached to a ferromagnetic plate with adhesive. Electrodestrips 14 and 15 may be economically made using steel strip (e.g. 0.01to 0.04″ thick), plated with metals such as copper with tin over nickel,gold flash over nickel, etc., to provide stable contact resistance.Electrical conductivity of steel electrode strips may be enhanced byelectroplating with copper or another conducting material.

Another construction of a laminated track (not shown) comprises a thinflexible circuit, such as a polyester-backed flexible printed circuitwith copper circuitry and dielectric base layer, i.e., a laminated“flexible flat cable” construction, laminated to a ferromagneticbacking. These thin flexible tracks may be coiled for efficientpackaging, or produced in rigid or semi-rigid strips with couplings. Theflat flexible track may also be constructed of a hardened temperedspring steel material to produce a deployable/retractable track (eitherself retracting like a tape measure or other constant force spring orretractable by winding). Other construction methods include stampedconductors mounted to insulators or combined with insert-moldingprocesses.

Flat tracks may also be environmentally sealed. For example, the trackelectrodes may be covered with an insulating tape which is die cut tofacilitate temporary removal of discrete sections of the tape to exposetrack contact points where placement of modules is desired (this wouldalso allow safe higher-voltage installations). This tape may be attachedwith a pressure-sensitive adhesive or may compriseelectrically-insulating plastic magnet material. A low compressiongasket may be disposed around the integral contact area, such that whenthe module is attached to the track, the contact interface is sealed.

By coring the substrate or providing a through hole for the permanentmagnet, the separation distance between the permanent magnet and theferromagnetic mounting surface can be made smaller than the substratethickness. This coring operation increases the magnetic force ofattraction for a given magnet size and type. For example, the separationdistance from the permanent magnet to the electrode ferromagneticcomponent may be made as small as the thickness of the contactmetallurgy of the module. Even when insulating sheets such as polyimide,polyester, or adhesives typically used in flexible circuitry are addedto support the contact metallurgy, this separation distance may bechosen to be on the order of a few tenths of one millimeter.

Spherical NIB (neodymium-iron-boron) magnets 3/16 inch diameter produceapproximately 1 lb of force through the integral contact when placedagainst a ferromagnetic surface. This is sufficient force to producereliable electrical interconnections resulting from the magnet pinchingthe integral contact between the magnet and ferromagnetic surface, aswell as adequate mechanical force to retain a variety of modularelectronic designs without additional mechanical attachment. ¼ inchdiameter magnets produce 1.6 pounds of force. Additional mechanical andmagnetic elements may be added to increase the mounting force as desiredfor a particular application.

FIG. 7 illustrates another form of track comprised of discrete rods orwires. In the track 18 illustrated in FIG. 7, electrical and magneticrails 19 are made from cylindrical or other cross sectional shapes offerromagnetic wire or rod, separated and held in place by insulators 20.Ferromagnetic core wire or rod may be plated with materials such ascopper, tin, nickel and gold to enhance electrical conductivity andprovide low electrical contact resistance. Two or more rods are utilizedfor positive and negative power connections 21. As shown in FIG. 7,three rods allow modules 1 to be installed at any location along the rodtrack 18 at various different angular orientations corresponding to theplanes formed by two adjacent rails. In this example with 3 rods, twodifferent angular orientations are possible with two positive and onenegative rail. If four rails are utilized in a square arrangement, withtwo common positive rails and two negative rails, modules 1 may beinstalled on any of the orthogonal sides. Modules 1 may be installed onthe outside of any two rails, or on the inside (180 degrees opposite) ofany two rails.

To accommodate non-regular spacing and tolerance variations in thedistance between the rails, elongated integral contacts 22 may beutilized as illustrated in FIG. 8 and FIG. 9. FIG. 8 is a bottom view ofmodule 23 having elongated integral contacts 22, and FIG. 9 is across-section view of FIG. 8. The formed or coined contact area 24 ofelongated integral contacts 22 is also elongated, in a direction that issubstantially perpendicular to the axis of the rail when the modules areinstalled onto the track. One or more elongated contacts may be utilizedin a module 23. Magnets 5 are loosely constrained in part by mechanicalfeatures 25 such that they are free to move within the elongated contactarea. Consequently, when module 23 is brought into proximity toferromagnetic rails 26, magnets 10 are attracted and automatically alignto rails 26, thus allowing proper magnetic retention and electricalinterconnection on non-uniformly spaced rails. FIG. 8 shows one of themagnets 5 displaced from its nominal center position by distance ‘y’.

FIG. 10 illustrates a magnetic interconnection to a ferromagnetic flattrack 13 (as previously described) using magnets 27 that are attached tothe circuitry 11 of substrate 2. In this case, the magnets wouldpreferably be coated with a material such as copper to make themelectrically conductive, and a passivating plating such as nickel-tin.Magnets 27 are attached to the substrate circuitry by electricallyconductive adhesives, soldering, etc. such that an electricallyconductive joint is formed. Electrical signals may be routed to the topside of the substrate through plated vias 44. Conducting magnets 27 mayalso be attached mechanically and optionally electronically to thecompliant flexible and cored contact structures described. As notedearlier herein the substrate can deform with substrate attachment of themagnets in order to be loosely constrained.

Referring to FIG. 11, other methods for forming magnetic integratedcontacts include magnetic electrical contacts which are electricallyconnected to a circuit substrate 2 (such as a PCB or flex circuit), butmay be attached to, or cooperate with, an additional intermediate partor housing 28. Contacts 29 may be routed through elongated openings,i.e. slots, 30 and disposed on the surface of housing 28. Contacts 29may also be insert-molded into a polymer housing with pressureconnection, or other methods such as soldering, to substrate 1.Substrate 1 and contacts 29 may also be integrated into a discreteflexible printed circuit, in which case contacts 29 are contained on thesurface of the flexible circuit, and may be routed to the outer surfaceof module 31 by various means such as wrapping around the edges ofhousing 28 or through slots 30. For example, contacts 29 may beintegrated onto a flexible printed circuit, and the flexible printedcircuit, and any heat generating components thereon, attached to ahousing 28 that is made of aluminum or other thermally conductivematerial.

Magnets 5 are located overlying contact pads 29 to generate directcontact force resulting from magnetic force generated between magnet 5and a second element with a ferromagnetic component such as rails 26.When direct contact pressure between permanent magnets, contactstructures, and secondary ferromagnetic elements is described in thisdisclosure, it is understood that permanent magnets 5 are not requiredto directly contact the electrical contact surfaces. Layers of substrateinsulator material or housing material may also be disposed between thepermanent magnet and contact surface; typically it would be preferablethat such layers be relatively low thickness in order to maximize themagnetic contact force when in use. This intermediate layer between thepermanent magnet and contact surface may also be shaped or formed totailor the contact outer contact surface geometry.

A flexible circuit can be threaded through a slot in a substrate ofsolid construction that does not contain any electronic circuitry suchas a metal plate and folded across a through hole and attached to ametal substrate as a lower-cost substrate alternative to the use of ametal clad printed circuit board. This is illustrated in FIG. 12-FIG. 17described below. The use of metal substrates in which the LED modulesare directly attached to the metal substrate with thermal conductingadhesive provides improved heat removal from the LED compared to thermalvias or enlarged circuit traces in a conventional FR4 printed circuitboard of the same size.

FIG. 12 through FIG. 17 illustrates another embodiment of an integralheat sink lighting module 32. FIG. 12 and FIG. 13 are top and bottomisometric views, respectively, of heat sink lighting module 50. FIG. 14and FIG. 15 are exploded top and bottom views respectively, and FIG. 16and FIG. 17 are top and bottom isometric views of the heat sink base 33with flexible printed circuit (FPC) 34 assembled. In this example heatsink lighting module 32 includes an integral heat sink base 33, madefrom cast aluminum, extruded aluminum or other thermally conductivematerials. Although the planar base and finned heat sink 33 are shown asa single unit, these elements may comprise separate structures. Thefinned portion may not be necessary for lower power applications and maybe eliminated. In this case, the unfinned heat sink base portion may befabricated from a piece of sheet metal.

In this example embodiment, FPC 34 contains at least one LED 35 attachedto the circuitry of FPC 34. FPC 34 may be attached to the surface ofbase 33 with thermally conductive adhesive to provide a low-resistancethermal path from the rear surface of LED 35. The FPC dielectric may beremoved from under the LED to create an opening to connect the bottomsurface of the LED subassembly to the metal base of the heat sink withthermally conductive adhesive to decrease thermal resistance.Alternatively, thermal vias and pads may be used on the FPC. As shown,the tabs of the FPC containing the FPC contacts 37 may be inserted intoslots 38 in base 33, and folded underneath base 33 such that theconductive contact pads are adjacent to magnet openings 39. The FPC maybe attached using adhesives or tape at the periphery around the contactpads 37. Lens/reflector 40 retaining features 41 overlying substratethrough holes assist in loosely retaining magnets 43. Contacts 37 arecompressed under magnetic force onto ferromagnetic tracks, or socketcontacts, to effect electrical and mechanical connection as describedpreviously. This example illustrates a single-piece housing 40containing lens and reflector features, magnet retaining features andperforations for ventilation. The module back surface may contain adielectric film or coating 42 to electrically insulate the surface,and/or provide a thermal interface function. This example may beutilized with the previously described tracks or may be incorporatedinto a socket.

An alternate embodiment of a magnetic lighting module employing LEDsubassemblies is shown in FIG. 18, FIG. 19 and FIG. 20. This type ofconstruction is compatible with utilizing OEM “first level package” LEDlight engines where LEDs are provided by the manufacturer integratedonto a substrate such as a metal-core-pcb (MCPCB) or ceramic substrate.FIG. 18 is an exploded view and FIG. 19 is a cross-sectional view of anassembled substrate MLM 44, ferromagnetic flat track electrode 45 andheat sink 6. Substrate 47 may be constructed from ametal-core-printed-circuit-board (MCPCB), a flexible printed circuitattached to a metal substrate, a ceramic or other circuit boardmaterials and combinations known in the art of electronic packaging.Generally substrate 47 would be constructed with one or more methods toprovide improved thermal conductivity through the substrate to dissipateand transfer heat from LED light engine or subassembly comprising anarray of LED die 48, whether by the substrate's bulk material properties(as in the case of an MCPCB's) or features such as thermal vias known tothose skilled in PCB fabrication, and/or auxiliary heat spreaders, metalslugs or other inclusions, fluid-filled heat pipes, etc. In thisexample, substrate 47 may be a MCPCB, with top layer circuit 49,aluminum core 50, and a protruding pad 51 to allow the surface of pad 51to be in contact with the surface of heat sink 46. Pad 51 may bereplaced or supplemented with a discrete part attached to the substrate,heat sink or track, or a pad of thermally conductive compliant material.Substrate MLM 44 contains features to loosely retain and locatepermanent magnets 52. In the subject example, magnets 52 are retained ina substrate opening by formed contact 53. These may be constructed ofvarious materials such as copper alloys plated with nickel, tin and/orgold, or a flexible printed circuit. In a substrate containing only asingle circuit layer on the top side of the substrate, the contacts areconfigured to make electrical contact with circuit pads 54, by springforce, soldering, conductive adhesives, etc. Contact 53 wraps around tothe bottom side of substrate 47 and contains a contact area 55 that iselectrically and mechanically connected to rail/track 45 by magneticforce between magnet 52 and the ferromagnetic component of rail/track45.

Contacts 53 may be designed to provide a downward preloading force ofpad 51 onto heat sink 46 by the configuration and offset of thesubstrate, track and contact dimensions. Contacts may be constructed ina variety of designs, such as the compliant contacts described in thereferenced patent applications or conventional spring contact elementdesigns and geometries. A thermal interface material such as thermallyconductive tapes, pads and greases may be added at the interface betweenthe substrate and the heat sink surface. When MLM 44 is attached totrack 45, magnetic force is produced between the ferromagnetic componentin track 45 and magnet 52, thereby compressing the bottom of contact 53to the electrode rails of the track to affect electrical contact, andbringing the raised thermally conductive surface 51 in close proximityto, or mechanically forced through spring action against, heat sink 46,thereby affecting a thermal conduction path. The MLM is mechanicallyretained onto grid/track by magnetic attraction, although additionalmechanical retention in the form of deflecting latches or threadedfasteners may also be employed. Substantially planar mechanical,electrical and thermal connections may also be made, without utilizingpreloading with spring components; in this case the MLM would bedesigned such that the thermal interface maintains no significantseparation, or a small controlled, gap (said gap filled with a thermalinterface material) to the heat sink without designed-in preload.Multiple MLM's may be easily attached or removed from the track andreconfigured. Portions of the permanent magnets 52 may also be incontact with the track electrodes and/or the contacts 53, and therebyprovide electrical conduction. Electrode rails may also be recessed intothe heat sink surface which reduces the amount of required compliancybetween the module and heat sink or height of the substrate protrusion.This is advantageous if relatively thick rails are required.

FIG. 20 illustrates a concentric substrate MLM 56 similar to theaforementioned example. Contacts 53 are offset at different distancesfrom the center of MLM 56 to facilitate attachment to concentriccircular electrodes 57. Construction of contacts 53 and correspondingconcentric electrodes 57 may be similar to the aforementioned lineartrack/grid designs. Other methods of constructing electrode 57 includeattachment of the conductors with ferromagnetic component to anunderlying retaining sheet 61, such as a thermally conductive tape, thatmay be applied to heat sink 4 with pressure sensitive adhesive (PSA)using previously described attachment methods.

Other methods of constructing a power distribution track, grid andelectrodes include the use of thin flexible circuit materials that areattached to a magnetic or ferromagnetic backing. The heat sink may alsocontain a ferromagnetic or magnetic component or be fabricated from aferromagnetic or magnetic material. Electrode tracks, grids and pads maybe attached to heat sinks with adhesives, tapes or other mechanicalmethods such as screws, rivets and barbs. An insulating layer is presentbetween the rails and electrodes as needed. The heat sink may serve asan electrically conductive path.

For example, referring to FIG. 21, a thin PCB or flexible circuit 58,comprised of an electrically conductive layer with electrode traces 66and dielectric layer 67 (e.g. polyester, polyimide, etc.) may belaminated to a relatively thin (˜0.005-0.03 inch thick) piece of steel59, which then is subsequently attached to a larger heat sink 46 madefrom Al or Cu; the less-thermally conductive steel may be bonded to themore thermally conductive aluminum or copper of the heat sink body usingthermally conductive adhesives or other cladding methods. These thincircuits, and the steel backing, may contain open areas in the circuitdielectric material to allow contact between the MLMheat-spreader/conductor 60 and base heat sink 46 material. The examplelighting module 62 comprises contact pads 63, magnet 5, and substrate64. Substrate 64 may be a conventional epoxy-glass construction,ceramic, or other substrates known to those skilled in the art; thermalvias 65 may be constructed to conduct heat to spreader/conductor pad 60made from aluminum, copper, or other thermally conductive material andsubsequently to heat sink. Substrate 64 may have a variety of circuitryand components such as LED's 4 and other control circuitry. The thin PCBor FPC dielectric may also contain thermally conductive fillers toenhance thermal conductivity; in this case, the thermal conduction pathmay be through the thermally conductive dielectric material. The closeproximity of the magnetic materials at the electrical contact positionprovides higher mechanical force to pull the heat spreader/conductor pad60 into intimate contact with the heat sink.

Such designs may be provided to a customer with the FPC circuitrylaminated to a ferromagnetic backing, with the ability to easilyseparate and assemble modular sections and attach to heat sinks withadhesives or mechanical methods. Mechanical installation (screws,rivets, barbs, clips, etc), thermally conductive adhesives and tapes,and magnetic components are various methods of attachment of electrodesto heat sinks and heat-spreaders.

FIG. 22 and FIG. 23 illustrate another embodiment of a magnetic lightingmodule 68 and socket style base 69. Lighting module 68 includeselectronic substrate 72 (e.g. metal core PCB) with LED area 70 andsubstrate contacts 71. Similar to previous descriptions, substrate 72may be a MCPCB with LED die mounted directly on the substrate, ordiscretely packaged LED's mounted onto substrate 72. Contacts 73 mayattach to the top-side electronic circuitry of substrate 72 and wraparound to the back side of substrate 72. Contacts 73 may be made ofspring materials such as copper alloys, flexible printed circuitmaterial, or other electrically conductive materials. Lens/reflector 74may be affixed to substrate 72, and in the example illustrated hasretaining features 75 to help loosely retain magnets 43. Lens/reflectorassembly 74 may have a variety of reflector, lens and outer housingshapes, with orientation and locking features.

Socket 69 may include a locating socket base ring 76 with ferromagneticcontacts 77. Contacts 77 contain a ferromagnetic element (e.g.tin-plated steel) whereby magnets 43 are magnetically attracted tocontacts 77, facilitating mechanical, electrical and thermal connectionto heat sink 46. Socket 69 may be inexpensively made using injectioninsert-molding of the contacts and locating ring. Socket assembly 69 maybe mounted to heat sink 46 with pressure sensitive adhesives, screws, orother adhesive and mechanical retention methods. If the surface of heatsink 46 is electrically conductive, an electrically insulating layer maybe placed between contacts 77 and the surface of heat sink 46 forisolation. The interface between the bottom of substrate 72 and heatsink 46 may contain a thermal interface material such as a thermally aconductive pad 79, or thermal grease. Socket base 76 and lighting module68 may contain other features such as mechanical orientation keys 80,mounting holes 81 and other mechanical retention features. Contacts 77are provided with a termination feature 82 suitable for electricalconnection to wires or electrical connectors. During installation,magnetic lighting module 68 is brought into proximity to socket assembly69 and the magnetic contacts affect electrical, mechanical and thermalconnection. For example, 0.19″ diameter, 0.25 lengthneodymium-iron-boron magnets produce approximately two pounds (900grams) of contact force for each magnet, and an LED lighting moduleapproximately 1.75″ diameter may be constructed as shown with a weightof approximately 25 grams. Thus, there is sufficient force to retain thelighting module and affect electrical and thermal contact.

The number and size of the magnets may also be varied to alter theretaining and contact forces; multiple electrical contacts and/or purelymechanical contacts and magnets may be incorporated into the base andlighting module. For example, FIG. 24 illustrates a socket 83 that haselectrical contact springs 84, and ferromagnetic pads 85; lightingmodule 86 contains electrical contact pads 84 and magnets 88 within thelighting module 86. Thus, ferromagnetic pads 85 and magnets 88 have noelectrical function, the magnets 88 and ferromagnetic pads 85 producethe force to compress electrical spring contacts 87 to contact pads 87,while simultaneously retaining the lighting module and producing thermalcontact to heat sink 46. Mechanical spring contacts may also besimilarly incorporated into the module. Since the spring contacts deformunder the magnetic force, the magnets may be rigidly fixed in themodule.

FIG. 25 illustrates a facetted heat sink 90 with multiple sockets 69affixed thereon, and multiple lighting modules 68 installed into sockets69. Wires 91 connect sockets 69 together or separately as appropriatefor the electrical design of the lighting modules and power supply 92. Afacetted linear heat sink as illustrated may be useful for varioustrack-style lighting fixtures. Sockets and lighting modules may beinstalled onto any style of heat sink or heat spreader capable ofdissipating the heat from the specified number of lighting modules, thegoal being to keep the LED device temperature below the specifiedmaximum operation junction temperature of the device. As an alternativeto wires, the track systems described previously may be utilized withsimilar facetted heat sink components.

FIG. 26-FIG. 30 illustrate rotary magnetic lighting modules 93 that maybe attached to and powered by ferromagnetic electrode rails 94. FIG. 26is an isometric view of modules 93, FIG. 27 is a top view, and FIG. 28is a side view of modules 93 and electrode rails 94. FIG. 29 and FIG. 30are side sectional views of module 93 and electrode rails 94illustrating pivoting of the modules. In this example, rotary module 93may comprise a finned aluminum body 95 that contain spherical orcompound-curved ferromagnetic contact pads 96. Ferromagnetic contactpads 96 are electrically connected to LED 97 (using wires 98, FPC'sand/or other electrical connection means). Rotary module 93 may beconstructed in multiple pieces (for example split vertically orhorizontally) to facilitate fabrication by casting, and for containingrequired circuitry within the module; the module may be constructed of acombination of materials such as injection-molded parts and thermallyconductive cast aluminum parts. Body 95 may also be made from ametal-plated polymer. Module 93 is electrically and mechanicallyattached to ferromagnetic track 94 utilizing contact magnets 99; contactmagnets 99 may be of a variety of shapes (e.g. discs, spheres, 3-Dshapes) and materials. Magnets 99 may be plated with materials such asnickel-tin or nickel-gold for good electrical conductivity and contactresistance. Contact magnets 99 may also be wrapped with a thin FPC, orother conductor material, whereby electrical conduction is through theapplied conductor instead of through the magnet itself. Contact magnetsmay also be a variety of materials and shapes, including polymer overmolded designs that incorporate the electrical conductors and otherauxiliary mechanical retention functions. Modules 93 may be rotatedalong any axis while retaining electrical and thermal connectionsbetween the contact magnets 99 and the ferromagnetic electrode rails 94and ferromagnetic contact pads 96. The contact magnets 99, contact pads94 and rails 94 are free to move and rotate relative to each other, andcooperate to maintain constant contact. Although they are notmechanically retained in the module, contact magnets may includemechanical features to maintain their position relative to the rails asthe module is rotated. The magnets may be preferentially retained on therail or module when the module is separated from the rail by controllingthe relative forces of magnetic attraction of the magnet to these twostructures.

FIG. 31 and FIG. 32 illustrate an embodiment of a can lighting fixture100, into which the rotary magnetic lighting module 93 of the previousexample may be installed to form a tilting/rotating recessed orsemi-recessed lighting fixture. A fixture socket 101 comprises a housing102, that loosely retains magnets 103, and a contact structure 104 inwhich electrical contact is made between the ferromagnetic contact pads96. The contact structure of the socket may be comprised of contact padsformed in FPC 107 with passive and active electrical components 106components and contact pads disposed on the FPC adjacent to the magnets103. Electrical contacts may also be formed utilizing conductive sheetmaterials such as copper alloys. Socket 102 may be installed into ashell 105, similar to commercially available “can lights”. FIG. 31illustrates the lighting module 62 installed vertically, and FIG. 32shows the lighting module tilted in the socket.

FIG. 33 and FIG. 34 illustrate another embodiment of a rotary lightingmodule with movable captured magnetic contacts 200 installed in canlighting fixture 108. In this example, the socket 109 may contain eithermagnets or ferromagnetic components 110. Module magnetic components 111are free to move within cavity 112, and thus when brought into proximityto a magnetic element 110 in the module, contacts 113 are compressedagainst the socket contacts 114 providing electrical contact andmechanical retention. Module magnetic components 111 may be many shapessuch as spheres, and multiple magnets may be utilized in conjunctionwith multiple smaller cavities. Contact pads 113 may be formed from anFPC or thin sheet materials such as copper alloys; in this embodiment,the contacts are not required to be ferromagnetic. At least one side ofthe socket-module contact pair contains a permanent magnet; the otherside of a mated contact may contain a ferromagnetic component orpermanent magnet. Note that the lighting modules shown in FIG. 33 andFIG. 34 may also be attached to the rail electrode assemblies previouslydescribed.

In the embodiments above, the LED light engine may be built directlyinto a higher level module during the manufacturing of the module. Thereare many choices in LED light engines with respect to electrical supplyrequirements, optical power and spectral characteristics, directionalityand uniformity of the light output, etc. These options create a verylarge number of possible combinations. Although the LEDs are efficientin their spectral output compared to incandescent lamps, they dogenerate waste heat that must be removed from the LED. As a result,there are also a number of different heat sinking requirements for lightengines using different LED modules and outputs. Although there is someflexibility in the application of external heat sinks in the embodimentsabove, there are a number of interfaces in the heat conduction to theexternal heat sink.

Embodiments described below provide an alternate approach suited forhigher performance, higher power lighting modules. Since higherperformance generally results from using higher cost components, greaterflexibility and modularity may provide significant savings by allowingcustomization closer to the end use location.

FIG. 35 through FIG. 38 illustrate another embodiment which providesmodularity and thermal management with higher efficiency due to fewerinterfaces between the LED element and the external heat sink. FIG. 35is a top exploded isometric view of compliant thermal modular lightingmodule 115; FIG. 36 is a bottom exploded isometric view; FIG. 37 andFIG. 38 are a top isometric view and bottom isometric view,respectively, of compliant thermal MLM 115.

MLM 115 is comprised of an LED subassembly 116, flexible conductorassembly 117, stamped spring 118, housing 119, and permanent magnets 120and may optionally include flexible protective film 121. The LEDsubassembly 116 may include an array of one or more semiconductor chipson a common substrate or may be an extended OLED. In this example,flexible conductor 117 may be a flexible printed circuit (FPC) such ascopper-clad polyester or polyimide common in the PCB industry. Flexiblecircuit 117 contains inner lead bond pads 122 that are electricallyattached to the respective LED bond pads 123 of LED 116. Shown in thisillustration are four radial contacts 124, at least two of which wouldbe electrically connected to LED pads 123 with circuitry on the flexiblecircuit 117 for supply of power to operate LED subassembly 116. Theadditional contact positions may be used for other functions such asdimming, color control, etc., or may be used only for mechanicalretention purposes. Many different form-factors and contact geometriesof the module are possible using the inventive concepts included in thisdisclosure.

Inner lead bond pads 122 of the FPC may be electrically attached to LEDsubassembly bond pads 123 by soldering, conductive adhesives/films orpressure connections. Flexible circuit 117 may be attached (withadhesives, insert-molding, etc.) to housing 119 on housing surfaces 125,covering magnet pockets 126 and retaining magnets 120. FPC modulecontacts 124 are positioned over pockets 126. FIG. 44 shows a detailedview of the stack up of the aforementioned structure). The flex circuitsurfaces 127 are preferably attached to the corresponding housingsurfaces 125 surrounding the magnet pockets 126; other parts of theflexible circuit 117 are loosely constrained, so that the flexiblecircuit is free to move to allow relative movement of the parts, toprovide compliancy for the thermal interface (described below) and toprovide compensation for initial mechanical tolerances and differentialthermal expansion effects during operation. In this example, FPC arms128 are free-floating and configured to allow axial displacement of theLED subassembly 116, flexible circuit 117, spring 118, and protectivefilm 121. Protective film 121 contains contact pad openings 129 and bondpad openings 130 and thus may be assembled between the top surface ofLED 116 and bottom surface of flexible circuit 117, and to the perimeter131 of housing 119, and surfaces of FPC adjacent to contacts 124, withadhesives such as pressure sensitive adhesives, to form a completelysealed structure. Other components and circuitry may be added to FPC 117to perform functions such as power conditioning, dimming, etc.

Housing 119 may be injection molded from transparent materials such asacrylic or polycarbonate and may contain features such as lensstructures 132 to modify the direction, distribution or spectral contentof the emitted light and keying features 133 to control matingorientation.

Protective film 121 seals the interior of the module 115, but is notrequired for the lighting functionality of the module. In addition, theLED and optics may be sealed around the perimeter of the LED with a foamor elastomer gasket or other sealant to increase environmentalisolation.

FIG. 37 and FIG. 38 shows a top and bottom assembled view, respectively,of module 115. As illustrated, the bottom side of the LED subassembly116 substrate is fully exposed on the bottom side of the module.Although full-exposure may be optimum for providing the largest thermalpath to the heat sink, the LED subassembly may alternatively be mountedon the top side of the flexible circuitry. In this case, an opening maybe cut out of the flexible circuitry or thermal conduction enhancementssuch as thermal vias through the flexible circuitry may be used toincrease thermal transfer to the heat sink from the bottom of the LEDassembly. Having the bottom of the LED subassembly exposed through anopening in the FPC or other substrates reduces the number of thermalinterfaces between the LED subassembly and the heat sink. In theseexamples, it is not necessary to conduct heat from the LED subassemblythrough an electrical or mechanical substrate or through a magneticmaterial, as is required in other prior art designs. Since the magnetsand circuit substrate connected to the LED assembly are not located inthe thermal path from the substrate to heat sink, thermal properties ofthe magnets and circuit substrate are not critical.

As described in earlier embodiments, the substrate of the module mayconsist of various materials such as epoxy glass printed circuit boards,ceramic substrates, metal-core PCBs, rigid-flex PCBs, molded circuitsubstrates, insert-molded metal and polymer assemblies, or otherelectronic substrate materials known in the electronic packaging arts.The substrate material underlying the LED subassembly may be removed toreduce the thermal interfaces between the back of the LED subassemblyand the heat sink. FPC 117 may also be replaced with a continuous metalfoil (e.g. non-magnetic materials such as copper, phosphor bronze) or ametal stamping if minimal circuit complexity is required. For example,referring to FIG. 39, a segmented stamped metal foil 134 is attached tohousing 119. Each segment may be electrically separated from othersegments or may be connected to other segments to form electricalcircuits through the addition of components 134 (such as resistors,diodes, etc.) between the foil segments. Such structures may beinsert-molded into housing 119, or attached with mechanical or adhesivemethods. The LED subassembly may be attached to the top or bottom sideof the metal segments. A flexible protective film may be added to thisassembly. Attachment of the LED to the metal foil 134 may be throughsoldering, conductive adhesives or pressure connection.

Referring to FIG. 40, the electrical, thermal and mechanical connectionof module 115 onto an external heat sink 46 is accomplished byinstallation onto ferromagnetic contacts 137 of socket 136, or the railand socket electrodes described previously. Although 4 magnetsassociated with 4 electrical contacts are shown, some magnet andferromagnetic pad pairs may be used to provide higher magnetic forceswithout participating in electrical conduction.

Referring to FIG. 41 through FIG. 44, the electrical, mechanical andthermal connection of module 115 to heat sink 46 and socket 136 isillustrated. FIG. 41 is a top view of module 115, socket 136 and heatsink 46. FIG. 42 is a cross-sectional view of module 115 prior toinstallation into socket 136 and FIG. 43 is a cross-sectional view ofmodule 115 assembled to socket 136 and heat sink 46; FIG. 44 is a detailview of the electrical contact area. Spring 118 is designed such thatwhen module 115 is seated onto the ferromagnetic contacts 137, spring118 is compressed to provide a compressive load between the base of LED116 and heat sink 46, the force generated by magnets 120 being attractedto ferromagnetic pads 137, while magnets 120 simultaneously providecontact force between FPC contacts 124 and socket contacts 137. Portionsof the flexible circuit, and the optional protective film 121, may beconfigured to provide the desired amount of movement and flexing of theLED and flexible conductor assembly to meet design objectives. Magneticattractive force between magnets 120 and ferromagnetic pads 137 pullsthe LED 116 substrate towards the heat sink, compresses spring 118, andprovides electrical contact and mechanical retention forces throughcontact pads 1248 and 137. Thus, the module LED subassembly 116 iscompressively loaded against heat sink 46 to provide thermal heatsinking at the same time that the module is also electrically connectedand mechanically retained to the heat sink. The back surface of LED 116may have a resilient or compliant thermal interface material 138, suchas a thermally conductive pad, phase-change material, grease, etc., toenhance thermal conductivity through the interface to the heat sink. Thethermal interface material may optionally provide a compressive springor compliant force instead of, or in addition to, a formed springmember. A boss or other raised area may also be included in the surfaceof the heat sink to increase compressive loading. The use of magneticattraction and the compliant mounting of the LED subassembly compensatesfor mechanical mismatches between elements for both electrical andthermal contact surfaces, and to reliably and predictably retainrequired thermal connection of the LED to heat sink over the life of theproduct, in one embodiment, even if the magnets are not looselyconstrained.

In the example embodiments illustrated in FIG. 35-FIG. 44, having anexposed external heat sink in thermal contact to the bottom of the LEDsubassembly, the magnets are located symmetrically outboard of the LEDsubassembly. This relative placement may provide more uniformcompression of an elastic thermal pad within the thermal contactinterface. If compliant materials such as thermal grease are used, thisrelative placement of magnets may not be a design consideration andasymmetric configurations and placement of magnets may be suitable. Therange of mechanical tolerances and thermal expansion effects may affectdesign choices of preloading, stiffness and inelastic deformationeffects in the contact pads and the electronic substrate used. Aconventional “rigid” substrate such as epoxy-glass printed circuit board(PCB), MCPCB, or molded circuit device that has been provided withrelief grooves or cuts, or specifically shaped beam springconfigurations may be sufficiently compliant to provide thermal contactwith the heat sink.

Functional prototypes of the designs shown in FIG. 35-FIG. 44 wereconstructed using four cylindrical NIB grade N52 magnets, 0.0875diameter×0.0875″ height, with a 0.007″ thick FPC, and housing diameterof 2″, and 0.375×0.375″ steel socket contact pads. Each magnet producesabout 1.3 pounds of retention force to each of the four contact padswith no spring present. A stamped spring was constructed to provideabout 3 pounds of compression load when fully seated into the socket.Consequently, each of the four contact positions has 1.3−0.75 lb=0.55lb/contact and retention force. The total weight of the module is lessthat 0.045 lb; thus 0.55 lb of force from each magnet is more thansufficient to produce excellent electrical contact and mechanicalretention of the lightweight module. Spring forces, the number and sizeof magnets and contacts may be easily varied for a given application.

These prototypes were compared to a commercially available modularlighting product (“Helieon” from Molex, Inc.). The Helieon productcontains an LED light engine that is mechanically mounted to a heat sinkby a coarse screw thread and springs. The Helieon product requires asocket assembly to be bolted to a heat sink, to which the replaceableLED module is installed with a twisting motion. The designs herein weretested and compared to the thermal performance and other factors. Usingthe same LED light engines (Bridgelux 800 lumen), power supplies andheat sink for comparison, the thermal performance of the designsdescribed herein was the same as, or better (depending upon thermalinterface materials used) as the Helieon product, while reducing thenumber of lighting module parts to one third, and reducing the size,volume and weight dramatically. In prototype tests, thermal performancedid not change appreciably with the attachment to a linear track systemon the socket heat sink that did not provide ferromagnetic contact padsfor two of the four magnets. This indicates that two magnets weresufficient to provide an efficient thermal conduction path from thelight engine to the heat sink.

Utilizing a foil/sheet stamping to provide the compressive spring forcemay also eliminate separate springs. For example, a spring similar tothe stamped foil 134 of FIG. 39 may be made from a non-magnetic springmaterial such as tin-plated phosphor bronze, which provides the springforce to compressively load the LED against the heat sink surface andprovide electrical conduction. Required preloading and compliancy of theLED thermal interface to the heat sink is thus accomplished with avariety of methods including spring function and features which areincorporated directly into the electronic substrate (PCB, FPC, moldedinterconnect, insert-molded metals, etc), separate non-electricallyconducting springs made from metals, elastomeric polymer springs,compliant elastomeric thermal interface materials, or combinations ofthe aforementioned.

FIG. 45 and FIG. 46 illustrate an LED module 139 comprising multiple LEDcomponents 140, multiple magnets 141, compression springs 142, compliantcircuit 143 housing 144 and socket 146 with ferromagnetic pads 145 andheat sink 46. FIG. 45 shows module 139 uninstalled, and FIG. 46 showsmodule 139 thermally, electrically and mechanically attached to socket146 and heat sink 46. The function of the elements of this multiple LEDmodule is similar to that described above, except that the modulecontains multiple LED subassemblies. As described previously, springsmay also be stamped single or “sheet” configurations, elastomericsprings, etc. Permanent magnets may be a variety of positions and sizes,and may be utilized for electrical, and/or compression for thermalcontact or mechanical retention of the module. Large arrays may beconstructed with uniform forces on the electrical contacts and thermalinterfaces using this approach, since compressive and contact forces areprovided locally by magnetic attraction of loosely constrained magneticstructures, and consequently close tolerances and rigid planarmechanical structures in the module are not required. This structureaccommodates attachment to irregular surfaces, and similar designs mayalso be made to conform to non-planar surfaces by making the housingstructure flexible or shaped to match a non-planar heat sink shape.

Although the embodiments above include an LED subassembly with a bottomsurface which is electrically insulated and is used for mechanicalsupport and thermal conduction, the bottom side of the LED substrate mayoptionally include areas for electrical conduction to the heat sink orto the socket. In this case, the use of graphite or other electricallyand thermally conducting materials may be used to assist with thermaland electrical efficiencies. In addition to LEDs, otherelectroluminescent lighting components modules that require thermalconduction separated from electrical interconnection may benefit fromthe embodiments described here.

The use of extended electrode rails that are not electrically insulatedare suitable to lower voltage applications due to the exposed electricalsupply voltage. The sockets that are described above can be designedsuch that they may be used with higher voltages as safely as aconventional mains supply Edison-type screw socket. Although heat sinksthat provide support for electrical wiring have been illustrated, thesmall size and thermal efficiency of the current embodiment provides amethod for making an LED replacement for conventional incandescent bulbscrew sockets 150. This is illustrated in FIG. 47. The lamp replacementfixture 147 comprises a heat sink 148 with conventional screw basecompatible with socket 150, power conversion and other electronics areincorporated within the base and/or heatsink structures. The modulecontains suitable ferromagnetic contact pad structures 149, connected tothe electronics within fixture 147 as described previously to functionwith MLM 115. The electronics convert the AC mains signal to a saferlower voltage AC or DC drive signal for the LEDs in the lighting module.Ferromagnetic contacts 149 on the top side of the heat sink of thisscrew base assembly provide magnetic attraction to the magnets in thelighting module 115 as previously described. Even when mains power isapplied to the screw socket, the MLM can be designed to require only lowvoltage is available on the heat sink magnetic socket assembly contacts.Bringing the lighting module in proximity to the socket assembly resultsin the mechanical, thermal and electrical connection as described above.The lens assembly may be shaped like a conventional bulb and may includephosphor or other materials or features that change the spectral contentor directionality of light. Compared to conventional one-pieceimplementations of replacement bulbs, the heat sink electronics assembly147 and the LED module can be individually replaced. The electrolyticcapacitors that are commonly found in the electronics that convert fromAC mains to LED drive voltages have a limited lifetime compared to LEDsand other solid state devices. The LED subassemblies are generally moreexpensive than the drive electronics. When something fails in theelectronics of the heat sink assembly of this embodiment, it is notnecessary to throw out the LED light engine that is part of the separatemagnetic lighting module. In addition, LED magnetic lighting modules canbe readily changed without tools to change the color or othercharacteristic of the emitted light without unscrewing the base from thescrew socket fixture. While a two-piece configuration is shown in thisfigure, the heat sink, screw socket and electronics portion may beseparated into more replaceable parts or may provide mounting contactsfor multiple magnetic lighting modules.

The lighting module designs described in the above embodiments can beconfigured for use with an extended wiring grid while retaining theirsimultaneous mechanical, electrical and thermal attachment. The powerdistribution flexibility and modular thermal heat sinking of this gridprovides more flexibility in positioning and thermal design than thelinear track, rail and socket electrode embodiments above.

FIG. 48 and FIG. 49 show an embodiment of an electrode grid 151constructed of a top electrode 152 containing openings 153, a centerelectrode 154 of opposite electrical polarity from top electrode 152,and a bottom electrode 155 (bottom electrode 155 facilitates attachmentof devices to both front and back sides of grid 151, although it isapparent that a grid may be constructed with only two electrode layers).In an embodiment, one or more of the electrodes contains a magneticcomponent; for example center electrode 154 may be made from tin-platedsteel sheet, and electrodes 2 and 4 from plated aluminum. Aluminum,copper and steel (used for the ferromagnetic component in the grid) areexamples of materials that electrodes may be fabricated from;additionally platings and claddings of various material combinations maybe utilized to tailor electrical conductivity, contact resistance, andcorrosion resistance and thermal conductivity. For example, aluminum andsteel may be plated with copper and tin to provide a suitable electricalcontact surface, and increase electrical and thermal conductivity in thecase of steel materials. There are many stack ups and material types andthickness that may be utilized.

For example, all electrodes of the grid may be constructed of aferromagnetic material (e.g. tin-plated steel), or electrode layers maybe a combination of ferromagnetic and non-magnetic materials such assteel, copper and aluminum. The electrode layer interfaces may beelectrically insulated from each other by using dielectric films,spacers, adhesives, and/or surface coatings or treatments such asanodization. Areas adjacent to openings 153 in the underlying electrodeare free from dielectric material to facilitate electrical contact tothe electrode surface to create an array of recessed electricalcontacts. As illustrated, top and bottom electrodes 152 and 155 may bothbe connected to the negative side of a power source 156 and the centerelectrode layer connected to the positive side of the power source. Ifdesired, one or both of these outer electrodes may be tied to electricalground or a third voltage level.

As an alternative embodiment (not shown) similar to FIG. 49, layer 152may be a positive electrode and layer 155 may be a negative electrode.Layer 154 in this case would be an electrically insulating layer withperforations. If the openings of layers 152 and 155 are offset from oneanother, then when viewing the stack from the layer 152 side, the innerside of layer 155 would be accessible through openings 153, and viceversa. As a result of the asymmetry in the electrodes of the grid for DCvoltages, modules may be designed that would function on a specific sideeven if the holes in the outer grids were the same size.

A benefit of this general design is that an outer surface of the gridthat is exposed to a user may be designed to not contain a voltagepotential difference on the surface or relative to electrical ground.The size, shape and aspect ratio of openings 153 may be configured suchthat the center electrode is not readily easily contacted except with anappropriately configured mating electrical device; this provides afurther level of electrical isolation of the exposed surface of the topgrid, and consequently the grid may be constructed for higher-voltageuse (e.g. greater than 24 volts by some safety standards), whileproviding reduced risk of accidental human contact.

Yet another advantage of the grid construction is that the relativelylarge surface area and thickness of the conductor layers are suitablefor carrying larger electrical currents if needed. Another object of thegrid structure is to provide an efficient heat-sink or heat-spreadingfunction to attached devices and/or thermal transfer to attached modularheat sinks. Materials and their thicknesses can be selected to provideheat transfer both in the plane of the grid or perpendicular to thegrid.

FIG. 50 and FIG. 51 illustrate an embodiment of a grid using aselectively shaped inner grid electrode 156. The inner electrodes may beconstructed with various shaped discrete ferromagnetic pads 157 totailor a degree of preferential orientation and alignment of a modulethat is placed on the surface of outer (non-magnetic) electrodes 158through local magnetic attraction differences. The selectively shapedgrid 156 contains an array of discretely shaped magnetic areas, joinedby electrically conductive members 159. In this example a punched sheetof conductive ferromagnetic material, such as tin-plated steel, containscircular pad areas 157 mechanically and electrically joined togetherwith smaller connecting members 159. When a magnetic module is placed onthe outer electrode 158 of the completed grid structure 160 (explodedview shown in FIG. 51), the module will be preferentially attracted tothe underlying shaped magnetic inner electrode pads 157. Electrodelayers 158, 156 and 161 are separated by a dielectric insulator (notshown) when assembled.

FIG. 52 through FIG. 55 shows an embodiment that demonstrates thefunction of the grid system and electrical, mechanical and thermalattachment of components thereto. In this example an LED grid lightingmodule 162 is illustrated. FIG. 52 is bottom isometric view of thelighting module. The general construction of the grid lighting modulemay be similar to the aforementioned lighting modules with compliantthermal mounting of the LED subassembly within the module. FIG. 53 is across-sectional view of grid lighting module 162, that is mechanically,electrically and thermally attached via magnetic force to one side ofgrid 151 and including an auxiliary heat sink 163 magnetically attachedto the opposite side of grid 151. FIG. 55 is a schematic view showingexamples of the varied locations possible for placement of module 162,schematically shown in FIG. 54, onto grid 151.

Referring to FIG. 52 and FIG. 53, the difference in this lighting modulefrom previous embodiments is that at least one contact is a protrudingcontact 164. Substantially planar contact 168 and auxiliary magnets 166are similar to module designs described previously. As shown, contact164 may be “floating”, in the sense that it is loosely constrainedwithin module 162 and has the ability to move at least perpendicular tothe grid to affect electrical contact to the inner electrode. Protrudingcontact 164 may be constructed from a permanent magnet with anelectrically conductive coating, or a non-conducting magnet, whichcauses a separate associated metal contact to move. Non-floating orsubstantially rigid, protruding contacts and rigid planar contacts maybe used, but will be less accepting of mechanical tolerance effects. Forthis reason, at least one of the magnetic structures should preferablybe loosely constrained so that it can move at a minimum in a directionperpendicular to the grid. Protruding contact 164 is designed such thatthe contact will fit into openings 153 to contact only the innerelectrode 154, while remaining insulated from the top grid surface. Oneor more layers of the grid 151 contain a ferromagnetic component. Forpurposes of discussion grid 151 is comprised of a center steel coreelectrode 154 (which may be plated or clad with materials such as copperand tin), and aluminum top and bottom surface electrode 152 and 155(which may be plated or clad with materials such as tin or copper), witha dielectric layer 167 separating the center electrode 154 from outerelectrodes 152 and 155.

The example of FIG. 53 shows the protruding contact 164 with aninsulating layer or feature 165 disposed adjacent to the contact 164 toprevent electrical contact to the vertical edges of openings 153 in topouter electrode 152. However, it is understood that other methods suchas providing an insulating layer (anodizing, thermally conductiveadhesives, polymers, paints, films) on the vertical edges of openings153 may also be used. Module 162 is attached to grid 151 using permanentmagnets 166 that are attracted to ferromagnetic core electrode 154.Planar contact 168 may be substantially flat, i.e. lacking any featurethat could extend through openings 153. Protruding contact 164 may beinserted into any grid opening 153, thereby contacting the centerelectrode 154, and planar contact 168 contacts any exposed area of thetop electrode 152, thus establishing a positive and negative connectionto the LED 116 through circuitry 169. Contacts 164 and 168 may bedirectly actuated with magnetic force from magnets 170 using magnets 170substantially adjacent to the contacts that are movable within housing172, or the contacts may be indirectly actuated with peripheral magnetssuch as auxiliary magnets 166—i.e. the protruding contact may be forcedinto contact with the recessed contact of the inner electrode bymagnetic force applied from another structure located remotely from thecontact location. Many contact designs are possible for the protrudingcontact, such as stamped and formed springs, pogo pins, conductionthrough magnets, flexible printed circuits, molded-interconnect-devicefeatures, etc. Planar contacts 168 may be constructed of a variety oftechniques and methods similar to those described in the references andin this document. A thermal interface material such as a thermal pad orgrease may be disposed between the LED 116 and grid 151, and may alsoserve as a compliant interface material. Grid electrode layers may alsobe constructed from flexible printed circuits, thin PCB's and stampedcircuitry.

The magnetic force may be designed to be sufficient to providemechanical, electrical and thermal connection of LED module 162 to grid151. Magnet sizes, shapes separation distances and material propertiesare readily varied to provide desired forces and properties. Grid 151may have significant thermal heat sinking capacity and may be adequateby itself for certain thermal loads of devices attached. Auxiliary heatsinks 163 may also be attached magnetically with magnets 171 ormechanically with fasteners to any position on either grid surfaces toenhance heat sinking capacity. Auxiliary magnetically attached heatsinks may also include thermal pads or other interface materials and mayinclude floating or fixed magnets. As shown in FIG. 53, magnets 171 arepositioned in cavities in the heat sink to increase the magneticattractive force. If desired, the heat sink may be electrically isolatedfrom the outer surface of the grid by using an electrically insulatinginterface that has adequate thermal conduction properties for theapplication (e.g. thermally conductive pads and tapes). Auxiliaryheat-sinking structures may also be mechanically installed into featuresin the grid, such as aluminum rods that screw into threaded holes in thegrid, or are press-fitted into holes in the grid.

FIG. 54 and FIG. 55 schematically illustrate the ability to randomlyplace modules 162 at any position on the grid surface, with the onlyrestriction being that protruding contact 164 must be located in a gridposition opening 153. Modules may be placed in uniformly or randomlyspaced patterns and rotations. Various sizes and shapes of modules arealso compatible with the grid system, as illustrated by the smallermodule 173 shown in FIG. 55.

FIG. 56 and FIG. 57 illustrate grid 151 with a variety of sizes andtypes of configurable magnetic modules (as previously described)attached at varied locations on the grid. FIG. 56 is an isometricexploded view showing a large square module 174, a small square module175 each with a protruding contact 164, and a planar contact 168, largeand small triangular magnetically attached heat sinks 176 and 177respectively, and square heat sink 178.

FIG. 57 shows an isometric view of the aforementioned componentsconfigured in another arrangement. Heat sinks may be of a variety ofshapes, sizes, fin orientations etc, and placed on the front and backsurfaces as required by the thermal load of attached modules; variousthermal interface materials such as thermal greases, tapes, pads, mayused between the heat sink and grid surface. FIG. 57 also illustrates aformed angled grid configuration 179. Grids described herein may be bentand folded in curved or planar configurations, or attached withelectrical and mechanical fasteners between grid panels. Panels may alsobe readily cut into different shapes while maintaining the electricalintegrity of the grid because of the extended planar layer construction.The grid structure may contain through-holes for air-flow though thegrid.

There are many contact configurations of the grid and modules that arepossible, including stepped protruding annular contacts, and moduleswith multiple protruding contacts. Grid structures may include more thantwo or three electrode layers, with mating stepped or varied heightprotruding contacts to contact different layers within the grid. Keyingand placement selectivity may be tailored by the geometry of theopenings in the grid and the mechanical design of the mating contacts.For example (not illustrated), outer electrode layers may containopenings of different diameters and or shapes such that differentcontact voltages are exposed in a segmented or multi-layer innerelectrode. The module may be designed with more than one protrudingcontact of different diameters, such that one protruding contact wouldpreferably be too large to fit through smaller diameter holes in theouter sheet. A voltage difference across the module would only occurwhen the larger protruding contact fit through one of the largerdiameter holes and the smaller protruding contact fit through one of thesmaller diameter holes. In this manner, even higher voltage hot andneutral AC supply voltages may be recessed under a continuous metalplane at ground potential.

FIG. 58 illustrates another embodiment of magnetic lighting module 185is mechanically, electrically and thermally attached to magnetic heatsink 181 and electrode grid 180 in which there are openings 184 in thegrid sized to provide a thermal conduction path between the bottom ofthe substrate of LED subassembly 116 and heat-sink 181. In thisembodiment, grid 180 contains a top electrode layer 182 (positivepolarity in this example) and a bottom electrode 183 (negative polarityfor example) separated by a dielectric layer 167 The bottom electrodelayer may be offset or smaller than the top electrode layer, and/orcovered with a dielectric along its edges as a safety measure to preventeasy access and contact/shorting of the electrodes from the frontworking surface of the grid. At least one of the grid electrodescontains a magnetic component. In this example, lighting module 185 ismagnetically and electrically attached to the top grid electrode 182with magnetic force from magnet 170 and magnetically compressed(positive in this example) contacts 186. A bottom electrode contact 187,which may comprise a compliant contact, is configured to be compressedbetween heat sink 181 and bottom (negative) electrode 183. Heat sink 181contains magnetic components 188. The force generated between themodule, heat sink and grid simultaneously compresses contact 187 tonegative LED electrode circuit structure 189, thereby providing positiveand negative connection to the LED module circuitry and components.Contact 187 may be part of the MLM 185 or part of the heat sink 181.Heat sink 181 may be modified to be electrically insulating with acoating or film. A thermally conductive pad 79, grease or other thermalinterface material may be located between the heat-sink, grid and LEDsubstrate. Similar designs may be used with the top side protrudingcontact methods, in conjunction with the grid openings which allowcontact between the LED substrate and heat-sink surface. Since an LED ora subassembly is spring-loaded/biased, the magnets do not need to beloosely constrained to accommodate some degree of system mechanicalvariation. However, if there are more than three electrical connectionsone or more loosely constrained magnets will provide more reliableperformance.

In a variation of the embodiment similar to the example of FIG. 58, grid180 does not require a magnetic component. In this embodiment, themagnetic components of the module and heat sink attract one anotherthrough the non-magnetic grid, accomplishing the mechanical, thermal andelectrical connection to the grid and from the heat sink to the module.One or both of the module and heat may sink contain a permanent magnet,or permanent magnet and ferromagnetic component combination. It ispossible to “key” various mechanical and electrical functions andorientations using the arrangement of the magnetic components(ferromagnetic and permanent magnet), and the polarity of permanentmagnetic components utilized. Such keying may be useful in matchingappropriate heat sinks with magnetic lighting modules having differentcooling requirements.

As described previously, magnetic components may be located directlyunderlying, overlying or adjacent to electrical contacts and directlyactuate the contacts, or displaced from the contacts and indirectlyactuate the contacts.

FIG. 59 illustrates an embodiment that utilizes a single layer track orgrid 190 using positive electrodes 191 and negative electrodes 192.Similar to the previous example, module 193, heat sink 181 and gridelectrodes 191 and 192 are mechanically, electrically and thermallyattached with magnetic components 204 contained in module 193 and heatsink 181, through positive contacts 194 and negative contacts 195 tocircuitry and components of LED subassembly 116. LED subassembly 116 iscompressed against heat sink 181 through a compliant thermal interfacematerial 79 as previously described. In the example of FIG. 59, only thecompliant thermal interface material deforms/compresses and no auxiliarysprings are utilized. An opening in substrate 203 is present to exposethe thermal interface material 79 attached to the bottom of LEDsubassembly 116. The LED subassembly 116 may be mechanically retainedwithin housing 201 and/or substrate 203. The LED may also be retainedand electrically attached by soldering to substrate 203 to pads on theLED and/or leads 202. Electrical interconnection to LED 116 andsubstrate 203 circuitry may be through soldering, pressure connectionsdirectly to substrate 203 or through secondary spring contacts,conductive adhesives, etc. Substrate 203 may be epoxy-glass PCB's,flexible circuits, molded interconnect substrates, ceramic, moldedlead-frames or other electronic substrates known in the electronicpackaging art.

Also similar to the previous example, electrodes 191 and 192 may benon-magnetic and magnetic components 204 of the module 193 and magneticcomponents 188 of the heat sink 181 may be attracted to one anotherdirectly through the grid or track as shown. The non-magnetic electrodesand support should be kept relatively thin to reduce the distancebetween the magnetic elements. In an alternate embodiment (unshown) theelectrodes comprise a magnetic component (e.g. tin-plated steel)attached to a magnetic or non-magnetic heat sink.

The track may consist of parallel rods suspended in space, orrectangular, circular, or other cross-sections. An open substantiallyplanar grid electrode may also be constructed from formed sheet metalmaterials with overlapping insulated conductors or insert-molded polymerand metal structures.

FIG. 60 shows an embodiment where thermal, electrical and mechanicalconnection is accomplished “indirectly” through the magnetic forcedirectly between the module magnetic components and heat sink magneticcomponents. The grid does not require magnetic components in thisexample. Magnetic components are displaced from the module LEDelectrical contacts 197 (positive polarity) and 198 (negative polarity).The magnetic components of the module 196 and heat sink 181 are locatedadjacent to one another through openings in the grid and do not interactwith the electrode components 191 and 192. Magnetic components (eithercombinations of permanent magnet-to-permanent magnet ormagnet-to-ferromagnetic) in the module and heat sink have the requiredforce to compress contacts 197 and 198 to their respective positive andnegative electrodes 191 and 192, and affect thermal contact between theLED 196 and heat sink 181. Due to the compliant loading on the thermalinterface from spring 142, magnets 188 and 204 may be fixed in positionin the thermal connection pathway and module while providing reliableelectrical and thermal conduction connections.

In all of these embodiments, thermal interface materials may be addedbetween the LED subassembly base and the external heat sink.

The contact structures may function as the compliant, spring, or memberfor mechanical loading of the LED to the heat sink, and the contactstructures may provide direct contact to the LED electrodes by pressureconnections.

Grids as described herein are not limited to the illustrated examples.For example, a grid may be any linear or area array of positive ornegative electrode components and may be fabricated primarily fromelectrically conductive materials, or a combination of conductors heldin position by dielectric materials.

Electrical, mechanical, and thermal interconnections to grids, modules,and heat-sinks described herein may be accomplished using a combinationof mechanical and magnetic means.

The heat sink component coupled to the lighting modules described hereinmay be configured primarily for mechanical and electrical connection ofthe lighting module to the grid, and have no significant thermalfunction.

Grid structures may be environmentally sealed by various methodsincluding covering or filling the openings in the outer grid surfacewith a dielectric tape or elastomer plugs. The grid covering may beremoved only where a module connection is desired.

Grid structures may be cut, folded, bent and electrically andmechanically attached in multiple panels.

Those skilled in the art to which the present invention pertains maymake modifications resulting in other embodiments employing principlesof the present invention without departing from its spirit orcharacteristics, particularly upon considering the foregoing teachings.Accordingly, the described embodiments are to be considered in allrespects only as illustrative, and not restrictive, and the scope of thepresent invention is, therefore, indicated by the appended claims ratherthan by the foregoing description or drawings. Consequently, while thepresent invention has been described with reference to particularembodiments, modifications of structure, sequence, materials and thelike apparent to those skilled in the art still fall within the scope ofthe invention as claimed by the applicant.

What is claimed is:
 1. A magnetic module comprising: an electricallypowered element that emits electromagnetic energy; a thermal conductionpathway, wherein the thermal conduction pathway extends from directlyunder the element that emits electromagnetic energy to the bottom of themodule; a first electronic substrate comprising: i. a dielectric layer;and ii. an electrical circuit comprising electrical conductors; a magnetcavity, wherein at least a portion of the lower surface of the magnetcavity comprises an element of the first electronic substrate; amagnetic structure contained at least partially within the magnetcavity, wherein the magnetic structure is not located in the thermalconduction pathway directly under the element that radiateselectromagnetic energy; an electrical contact that projects below anadjacent portion of the bottom surface of the module; and a springmember responsive to a mechanical force applied to the bottom surface ofthe thermal conduction pathway wherein deflection of the spring memberresults in movement of the bottom surface of the thermal conductionpathway relative to the top surface of the module.
 2. The magneticmodule according to claim 1 wherein the first electronic substratecomprises a flexible circuit; wherein the electrically powered elementthat radiates electromagnetic energy is electrically attached to theflexible circuit; and wherein the electrical contact comprises a portionof the flexible circuit.
 3. The magnetic module according to claim 1wherein the electrically powered element that emits electromagneticenergy comprises: a. a second electronic substrate wherein the secondelectronic substrate is electrically connected to the first electronicsubstrate; and b. a solid state light emitter wherein the solid statelight emitter is mounted on the top surface of the second electronicsubstrate.
 4. The magnetic module according to claim 3 wherein the firstelectronic substrate comprises a through hole; and wherein the secondelectronic substrate is electrically connected to the first electronicsubstrate with the solid state light emitter positioned above or belowthe through hole.
 5. The magnetic module according to claim 3 whereinthe dielectric layer of the first electronic substrate comprises awindow; and wherein the electrical connection between the firstelectronic substrate and the second electronic substrate comprises asolder connection extending through the window in the dielectric layerof the first electronic substrate.
 6. The magnetic module according toclaim 1 wherein the magnetic structure comprises a permanent magnet thatprovides at least two pounds of magnetic attraction force.
 7. Themagnetic module according to claim 1 wherein at least a portion of themagnetic structure is positioned within about 0.3 mm of the bottomsurface of the module proximate the magnet cavity.
 8. The magneticmodule according to claim 1 wherein at least a portion of the magneticstructure is loosely contained within the magnet cavity.
 9. The magneticmodule according to claim 8 wherein at least a portion of the electricalcontact is located below at least a portion of the magnet cavity andwherein reducing the projection distance of the electrical contactresults in movement of the magnetic structure toward the top of themodule.
 10. The magnetic module according to claim 1 comprising anelectrical circuit path; wherein the electrical circuit path extendsbetween the electrical contact and the element that radiateselectromagnetic energy; wherein the dielectric layer of the firstelectronic substrate comprises a window; and wherein the electricalcircuit path passes through the window in the dielectric layer of thefirst electronic substrate.
 11. The magnetic module according to claim 1comprising an electrical circuit path that extends from the top surfaceof the first electronic substrate to the bottom surface of the module;wherein the electrical circuit path comprises a spring member; andwherein the electrical contact comprises a portion of the spring member.12. The magnetic module according to claim 1 further comprising ahousing wherein a boundary of the magnet cavity comprises the housing.13. The magnetic module according to claim 12 wherein the housingcomprises a radiation cavity; wherein electromagnetic energy is emittedinto the radiation cavity; and wherein the housing comprises materialthat transmits electromagnetic radiation.
 14. The magnetic moduleaccording to claim 13 wherein at least a portion of the magnet cavity isseparated from the radiation cavity.
 15. The magnetic module accordingto claim 12 comprising means for environmental sealing of the interiorof the module wherein the means for environmental sealing comprise thehousing and the first electronic substrate.
 16. A magnetic modulecomprising: an electrically powered element that radiateselectromagnetic energy having a thermal conduction interface on thebottom side of the element; a thermal conduction pathway, wherein thethermal conduction pathway is configured to be in thermal contact withthe thermal conduction interface of the element that radiateselectromagnetic energy; an electrical contact pad; an electrical pathbetween the electrical contact pad and the element that radiateselectromagnetic energy; a first electronic substrate comprising: i) anelectrical circuit trace comprising a portion of the electrical pathbetween the electrical contact and the element that radiateselectromagnetic energy; ii) a dielectric layer wherein at least aportion of the dielectric layer supports the electrical circuit trace;and a cavity, wherein a portion of the boundary of the cavity comprisesan element of the first electronic substrate; and a magnetic structure;wherein the magnetic structure is loosely constrained and located atleast partially within the cavity; and wherein the magnetic structure isnot located in the thermal conduction pathway directly under the elementthat radiates electromagnetic energy.
 17. The magnetic module accordingto claim 16 wherein the electrical contact pad comprises a metal foil.18. The magnetic module according to claim 16 comprising a secondelectronic substrate mechanically coupled to the bottom side of thefirst electronic substrate wherein the element that radiateselectromagnetic energy is mounted on the top side of the secondelectronic substrate and wherein the thermal conduction pathwaycomprises a portion of the second electronic substrate; and wherein thefirst electronic substrate further comprises a radiation through holewherein the radiation through hole is sized to provide an overlap ofportions of the first and second substrates and positioned so that theradiation emitted from the top side of the element that radiateselectromagnetic energy is not obstructed by the first electronicsubstrate.
 19. The magnetic module according to claim 18 comprising anopening in the dielectric layer of the first electronic substrateadjacent to the radiation through hole in the first electronic substratewherein the electrical circuit path from the electrical contactstructure on the first electronic substrate to the element that radiateselectromagnetic energy on the second electronic substrate extendsthrough the opening in the dielectric layer.
 20. The magnetic moduleaccording to claim 16 wherein the first electronic substrate comprisesat least one of an epoxy glass printed circuit board, a ceramicsubstrate, a metal-core printed circuit board, a rigid-flex printedcircuit board, a molded circuit substrate, and a flexible circuit. 21.The magnetic module according to claim 20 wherein the thermal conductionpathway comprises at least one cavity filled with material having higherthermal conductivity than the thermal conductivity of the dielectriclayer of the first electronic substrate.
 22. The magnetic moduleaccording to claim 16 wherein the first electronic substrate comprises aprinted circuit board of laminar structure comprising at least one metalfoil layer and at least one dielectric layer and wherein the electricalcontact pad comprises a portion of the foil layer of the printed circuitboard.
 23. The magnetic module according to claim 16 comprising a metalplate having top and bottom surfaces wherein the metal plate comprises aportion of the thermal conduction pathway under the element thatradiates electromagnetic energy; and wherein the first electronicsubstrate comprises a flexible printed circuit comprising: a. at leastone flexible electrical conductor layer; and b. at least one flexibledielectric layer; and wherein the flexible circuit is shaped to haveportions located on the top surface and the bottom surface of the metalplate.
 24. The magnetic module according to claim 23 wherein the metalplate comprises one or more through holes and wherein the magnet cavitycomprises a through hole in the metal plate and wherein the flexiblecircuit is routed through a through hole in the metal plate.
 25. Themagnetic module according to claim 16 wherein a portion of the firstelectronic substrate comprises slits or thinned regions configured toincrease mechanical compliancy.
 26. The magnetic module according toclaim 16 further comprising a housing wherein the housing extends overthe top of the magnetic structure and the element that radiateselectromagnetic energy.
 27. A magnetic module comprising: a. one or moreelectrically powered elements that radiate electromagnetic energy; b.two or more electrical contacts configured for providing electricalpower to the one or more elements that radiate electromagnetic energywhen the module is coupled to a magnetic fixture comprising electricalconnections; c. a thermal conduction pathway for removing heat from themodule wherein the thermal conduction pathway terminates in a thermalconduction pathway interface on the bottom side of the module locateddirectly under the one or more elements that radiate electromagneticenergy; d. one or more magnetic structures comprising a permanent magnetconfigured to provide electrical contact biasing forces on the two ormore electrical contacts when the module is coupled to a magneticfixture comprising electrical connections wherein the magneticstructures are not located directly under the one or more elements thatradiate electromagnetic energy; and e. a compliant structure configuredto provide a mechanical biasing force on the thermal conduction pathwayinterface when the module is coupled to a magnetic fixture, wherein themagnitude of the mechanical biasing force on the thermal conductionpathway interface is not essentially the same as the sum of theelectrical contact forces on the two or more electrical contacts whenthe module is coupled to a magnetic fixture.
 28. The magnetic moduleaccording to claim 27 wherein the mechanical biasing force on thethermal conduction pathway interface is more than about twice themagnitude of the mechanical biasing force on one of the electricalcontacts when the module is coupled to a magnetic fixture comprisingelectrical connections.
 29. The magnetic module according to claim 27wherein at least one of the electrical contacts and the thermalconduction pathway interface protrude below at least a portion of thelower surface of the module that is located between the at least oneelectrical contact and the thermal conduction interface.
 30. Themagnetic module according to claim 29 wherein the protrusion distance ofthe at least one of the electrical contacts and the thermal conductionpathway interface is configured to reduce when the module is coupled toa magnetic fixture.